Author Interviews, Vitamin D / 15.03.2017

MedicalResearch.com Interview with: [caption id="attachment_32963" align="alignleft" width="177"]Dr. Sheila Sprague, PhD Assistant Professor, Research Methodologist McMaster University Dr. Sheila Sprague[/caption] Dr. Sheila Sprague, PhD Assistant Professor, Research Methodologist McMaster University MedicalResearch.com: What is the background for this study? What are the main findings? Response: Previous research has found that daily administration of vitamin D is important for maintaining bone homeostasis. There has been an increased interest among the orthopaedic community regarding vitamin D supplementation and patient outcomes following fractures. Using data from the FAITH trial (NCT01908751), a multicenter randomized controlled trial that compared cancellous screws versus sliding hip screws in patients over the age of 50 with femoral neck fractures, we: 1) determined the proportion of patients consistently taking vitamin D following hip fracture surgery and 2) determined if supplementation was associated with improved health related quality of life and reduced re-operation. Patients enrolled in the FAITH trial were recruited from 81 clinical sites in 8 countries over a 6-year span. We asked a subset of them about vitamin D supplementation and categorized them as consistent users, inconsistent users, or non-users. The final analysis included 573 patients and we found that a surprisingly low proportion of elderly hip fracture patients are consistently taking vitamin D (18.7% of patients reported never taking vitamin D, 35.6% reported inconsistent use, and 45.7% reported consistent use). We also found that vitamin D was associated with a statistically (p=0.033), but not clinically, significant improvement in health-related quality of life following a hip fracture. Lastly, supplementation was discovered to not be associated with reduced re-operation (p=0.386).
Author Interviews, Endocrinology, Lancet, OBGYNE, Pediatrics, Vitamin D / 07.03.2017

MedicalResearch.com Interview with: Audry H. Garcia PhD Scientist Department of Epidemiology Erasmus MC, University Medical Center Rotterdam Rotterdam, the Netherlands  MedicalResearch.com: What is the background for this study? Response: Fetal bone mineralisation requires an adequate transfer of calcium to the fetus by the end of the pregnancy. Considering that vitamin D is required to maintain normal blood concentrations of calcium, adequate 25-hydroxyvitamin D (25[OH]D) concentrations in pregnant women seem to be crucial for bone development of the offspring. Maternal vitamin D deficiency during pregnancy has been associated with abnormal early skeletal growth in offspring and might be a risk factor for decreased bone mass in later life. Several studies have linked vitamin D deficiency in fetal life to congenital rickets, craniotabes, wide skull sutures and osteomalacia. However, the evidence of long-lasting effects of maternal vitamin D deficiency during pregnancy on offspring’s skeletal development is scarce and inconsistent, and has led to contradictory recommendations on vitamin D supplementation during pregnancy.
Author Interviews, Infections, Lancet, Vitamin D / 14.02.2017

MedicalResearch.com Interview with: Dr. Adrian R Martineau B Med Sci DTM&H MRCP PhD Clinical Professor of Respiratory Infection and Immunity Centre for Primary Care and Public Health. Blizard Institute, Barts and The London School of Medicine and Dentistry Queen Mary, University of London MedicalResearch.com: What is the background for this study? Response: In addition to its well-known effects on bone, Vitamin D has also been shown to boost immune responses to viruses and bacteria that cause respiratory infections in lab experiments. In order to see whether these effects translate into a health benefit, a total of 25 clinical trials of vitamin D supplementation to prevent various respiratory infections have been carried out in around 11,000 people living in 14 different countries over the last decade. These trials have yielded conflicting results: in some, vitamin D reduced the risk of infections, but in others it did not. The reason why vitamin D ‘worked’ in some trials, but not in others, has been the subject of much debate. In order to answer this question, we assembled an international consortium of investigators and compiled the raw data from every trial into a single database containing information from 10,933 people in total. This allowed us to run sub-group analyses to determine whether particular groups of people benefit more from vitamin D supplementation than others.
Author Interviews, Technology, Vitamin C, Vitamin D, Vitamin K / 17.01.2017

MedicalResearch.com Interview with: [caption id="attachment_31318" align="alignleft" width="130"]Adrienne R. Minerick, Ph.D. Associate Dean for Research & Innovation, College of Engineering Assistant to the Provost for Faculty Development Professor, Chemical Engineering Michigan Technological University Houghton, MI 49931 Dr. Adrienne Minerick[/caption] Adrienne R. Minerick, Ph.D. Associate Dean for Research & Innovation, College of Engineering Assistant to the Provost for Faculty Development Professor, Chemical Engineering Michigan Technological University Houghton, MI 49931 MedicalResearch.com: What is the background for this study? What are the main findings? Response: With seed funding from the Gerber Foundation, we asked two scientific questions. 1. Are vitamins present in tears and could we reliably detect them? 2. Do the vitamin levels in tears correlate with the vitamin levels in blood? This research, conducted by recent PhD graduate Maryam Khaksari, illustrated that vitamins are present in tears. The majority of the essential vitamins are water soluble, which were present in tears in higher concentration than fat soluble vitamins. Given that tears are 98% water, this result wasn’t surprising. This study developed up protocols to reliably detect both water and fat soluble vitamins. The limits of detection and limits of quantification did vary by vitamin, so there is ample room to improve this technique. The second question was answered by a small clinical trial with UP Health: Portage Hospital’s Pediatric Clinic. During the 4-month well-baby check-up, willing parents and their infant each donated both a blood sample and a tear sample. Vitamin concentrations were determined in the samples and correlations quantified. Fat soluble vitamin K showed the strongest concentration correlation between blood and tears. The strength of additional vitamin correlations were noted. These early-stage results demonstrate that vitamin screening from a single drop of tears (35uL or microliters) is feasible – with additional refinement.
Author Interviews, Nature, Pain Research, Vitamin D / 09.01.2017

MedicalResearch.com Interview with: [caption id="attachment_31087" align="alignleft" width="146"]Dr-Jyrki-Virtanen.jpg Dr. Jyrki Virtanen[/caption] MedicalResearch.com: What is the background for this study? What are the main findings? Response: Formation of vitamin D in the skin with UVB light from the sun is a main source of vitamin D during summer months, but in the winter months the UVB light is too weak for vitamin D production. Headache prevalence has been suggested to be related to increasing latitude (less UVB light throughout the year) and possibly to be less prevalent during summer (more UVB light), which suggests a possible role for vitamin D exposure. Some previous small studies have suggested that low serum vitamin D levels might be associated with more frequent headache or migraine. Our study included 2601 men from the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) from eastern Finland, aged 42-60 years in 1984-1989, which makes it one of the largest studies so far regarding vitamin D and headache. In our study chronic headache (occurring weakly or daily) was reported by 250 men, and men reporting chronic headache had lower serum vitamin D levels than others. When we divided the study population into four groups based on their serum vitamin D levels, the group with the lowest levels had over a twofold risk of chronic headache in comparison to the group with the highest levels. Chronic headache was also more frequently reported by men who were examined outside the summer months of June through September.
Author Interviews, Nutrition, Ovarian Cancer, Race/Ethnic Diversity, Vitamin D / 19.09.2016

MedicalResearch.com Interview with: [caption id="attachment_24508" align="alignleft" width="200"]Bo (Bonnie) Qin, Ph.D. Postdoctoral Scholar Rutgers Cancer Institute of New Jersey New Brunswick, NJ 08903 Dr. Bo Qin[/caption] Bo (Bonnie) Qin, Ph.D. Post-Doctoral Associate Rutgers Cancer Institute of New Jersey New Brunswick, NJ 08903 MedicalResearch.com: What is the background for this study? Response: Ovarian cancer is the leading cause of death from gynecologic cancer in the US. African-American patients diagnosed with ovarian cancer tend to have a worse 5-year survival rate compared to their European-American patients. Therefore, identifying preventive factors in African-Americans women is particularly important. African Americans tend to consume less calcium and vitamin D from dietary sources, due to a higher prevalence of lactose intolerance, and supplemental intake. Meanwhile, darker color of the skin reduces the synthesis of vitamin D upon sun exposure. They together place African-American women at risk for calcium and vitamin D deficiency. It remains unknown whether calcium, vitamin D, lactose and dairy products are associated with ovarian cancer risk in African-American women and our study aimed to answer this question.
Author Interviews, Diabetes, Vitamin D / 16.09.2016

[caption id="attachment_27954" align="alignleft" width="133"]Elisa Benetti, PhD Elisa Benetti, PhD[/caption] MedicalResearch.com Interview with: Dr. Elisa Benetti PhD Department of Drug Science and Technology University of Turin Turin, Italy MedicalResearch.com: What is the background for this study? Response: The idea for this study comes from the debate on the role of vitamin D supplementation in the prevention or progression of type 2 diabetes (T2DM). Epidemiological data point at a strong association between vitamin D deficiency and T2DM prevalence, however a causal relationship is still lacking. Here we wanted to explore the effect of vitamin D administration on insulin-sensitivity, particularly focusing on skeletal muscle, which is a crucial tissue in the maintenance of glucose homeostasis and which was suggested to be a tissue target of vitamin D. Using a murine model of insulin-resistance induced by a High Fat-High Sugar Diet (HFHS), we demonstrated that a vitamin D supplementation (7 μg•kg-1, i.p. three times/week) was able to revert the deleterious effects evoked by the diet, including the increase in body weight and in the HOMA-IR (a parameter of insulin resistance) and the glucose tolerance impairment. Consistently, at the muscle level, vitamin D increased the insulin sensitivity by reducing tissue inflammation and fat accumulation (myosteatosis). These effects are due, at least in part, to the inhibition exerted by vitamin D on carboxymethyl-lysine (CML) production, one of the main Advanced Glucose End-products (AGEs), and on its receptor RAGE. Collectively, our data indicate the ability of vitamin D to reduce the development of muscle insulin resistance, the primary defect in T2DM patients.
Author Interviews, Nutrition, Pediatrics, Vitamin D / 31.08.2016

MedicalResearch.com Interview with: [caption id="attachment_27553" align="alignleft" width="125"]Dr-Ben-Wheeler.jpg Dr. Ben Wheeler[/caption] Dr. Ben Wheeler MB ChB(Otago) DCH CCE FRACP Senior Lecturer / Paediatrician / Paediatric Endocrinologist Department of Women’s & Children’s Health : Te Tari Hauora Wāhine me te Tamariki Dunedin School of Medicine MedicalResearch.com: What is the background for this study? Response: Vitamin D is essential for calcium and bone metabolism. It is unique among vitamins in that it is mainly derived from synthesis in the skin after exposure to UV-B radiation. In the absence of fortification, few foods are rich in vitamin D, including human milk, which contains very low amounts. Breastfeeding infants in higher latitude countries such as New Zealand, much of North America and Central/Northern Europe are at risk of vitamin D deficiency. The most profound manifestation of vitamin D deficiency in growing children is rickets, characterized by bone deformities, impaired growth, biochemical abnormalities, and depending on the severity of deficiency, seizures. Studies also identified a number of common factors that potentially affect the risk of rickets, including darker pigmented skin, maternal vitamin D deficiency during pregnancy, season of birth, and age. A potential alternative strategy to improve the vitamin D status of breastfed infants is high-dose vitamin D supplementation to pregnant and lactating women. This would be attractive from a compliance perspective, promote exclusive breastfeeding, and treat both the mother and her infant. Thus, the primary aim of this randomized, placebo-controlled study was to determine the effect of two different monthly doses of maternal vitamin D supplementation on the vitamin D status of non–vitamin D–supplemented breastfed infants and their mothers.
Author Interviews, Endocrinology, JCEM, NIH, Vitamin D / 08.08.2016

MedicalResearch.com Interview with: [caption id="attachment_26830" align="alignleft" width="100"]Quaker Harmon M.D., Ph.D. Epidemiology Branch National Institute of Environmental Health Sciences Research Triangle Park, NC 27709 Dr. Quaker Harmon[/caption] Quaker Harmon M.D., Ph.D. Epidemiology Branch National Institute of Environmental Health Sciences Research Triangle Park, NC 27709 MedicalResearch.com: What is the background for this study? What are the main findings? Response: Vitamin D is important for bone health. In the United States many women are vitamin D deficient. Vitamin D does not naturally occur in many foods, however some foods are fortified with vitamin D. Supplements and sunshine are the most reliable sources of vitamin D. Previous studies suggested that women using birth control pills containing estrogen had higher levels of vitamin D. These studies were generally small and were not always able to examine important factors such as time spent outside. We were interested in examining the association between hormonal contraception and vitamin D levels in a larger group of women. We found that women who use estrogen-containing contraception had a 20% increase in their vitamin D levels. This increase was not due to time spent outside or behaviors related to choice of contraception. The magnitude of increase for hormonal contraception was smaller than for regular use of a supplement containing vitamin D.
Author Interviews, Genetic Research, Prostate Cancer, Race/Ethnic Diversity, Vitamin D / 02.08.2016

MedicalResearch.com Interview with: [caption id="attachment_26679" align="alignleft" width="142"]Gerard (Gary) Hardiman, Ph.D Professor, Department of Medicine Professor Department of Public Health Sciences Bioinformatics Director Center for Genomic Medicine Medical University of South Carolina Charleston, SC 29425 Dr. Gerard Hardiman[/caption] Gerard (Gary) Hardiman, Ph.D Professor, Department of Medicine Professor Department of Public Health Sciences Bioinformatics Director Center for Genomic Medicine Medical University of South Carolina Charleston, SC 29425 MedicalResearch.com: What is the background for this study? What are the main findings? Response: There are significant racial disparities in prostate cancer outcomes. The disease disproportionately affects African American men in terms of incidence, morbidity, and mortality, even after adjustment for stage. African American men have a 2- to 3-times increased risk of developing prostate cancer and have a greater mortality rate compared to European American men. We carried out a prospective clinical study aimed at examining the effects of vitamin D3 supplementation at 4,000 IU per day for two months in male subjects who selected surgical removal of the prostate (prostatectomy) as a definitive treatment for their prostate cancer. The primary goal of this study was to examine molecular differences in gene expression patterns relevant to prostate cancer disparities between African American and European American men, and investigate the global effects of vitamin D3 supplementation on the prostate transcriptome. We carried out genome wide expression profiling experiments using high throughput (HT) RNA sequencing. Transcriptional profiles of each of the patient’s tissue samples were generated and systems level analyses were performed.
Author Interviews, Blood Pressure - Hypertension, Vitamin D / 08.07.2016

MedicalResearch.com Interview with: Dr. Nicola Veronese University of Padova Department of Medicine - DIMED, Geriatrics Division Padova, Italy MedicalResearch.com: What is the background for this study? What are the main findings? Response: In the last 5 years, some studies investigated the possible association between hypovitaminosis D and orthostatic hypotension. However, all these studies were cross-sectional,  not disentangling if hypovitaminosis D precedes or follows orthostatic hypotension. In our work, we reported that low vitamin D at baseline predict the onset of orthostatic hypotension at follow-up in older people. This association was stronger in women than in men.
Author Interviews, Multiple Sclerosis, PLoS, Vitamin D / 19.05.2016

MedicalResearch.com Interview with: Ms Emily Weiss PhD student Centre for Population Health Sciences The University of Edinburgh

MedicalResearch.com: What is the background for this study? What are the main findings?  Response: Vitamin D deficiency, a marker of low ultraviolet (UV) exposure, is common in Scotland; both have been shown to work independently as risk factors for multiple sclerosis (MS). Orkney, situated to the north of mainland Scotland has a very high prevalence of MS. We therefore wanted to understand how vitamin D in Orkney compares to mainland Scotland’s vitamin D, and also what may be determining vitamin D levels in Orkney.
Author Interviews, Pediatrics, Vitamin D / 02.05.2016

MedicalResearch.com Interview with: [caption id="attachment_23968" align="alignleft" width="200"]Hope Weiler, RD (CDO), PhD Associate Professor Canada Research Chair tier I, Nutrition and Health Across the Lifespan, Director, Mary Emily Clinical Nutrition Research Unit School of Dietetics and Human Nutrition McGill University Macdonald Campus Ste Anne de Bellevue, QC Dr. Hope Weiler[/caption] Hope Weiler, RD (CDO), PhD Associate Professor Canada Research Chair tier I, Nutrition and Health Across the Lifespan, Director, Mary Emily Clinical Nutrition Research Unit School of Dietetics and Human Nutrition McGill University Macdonald Campus Ste Anne de Bellevue, QC  MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Weiler: Vitamin D is a fat soluble with important functions in growth during infancy and childhood, especially for the skeleton. It is for this reason that many policy recommendations for infants stipulate that newborn infants receive a supplemental form of vitamin D. In Canada, it is recommended by Health Canada (www.hc-sc.gc.ca) that newborn infants receive 400 international units of vitamin D from birth to a year of age or until that amount can be obtained from diet. In Canada, older children and adults can make vitamin D when their skin is exposed to direct sunlight between April and October; however, parents are advised to avoid placing their infants in direct sunlight. Thus supplemental vitamin D is particularly important in infancy. Often newborn infants begin life with low body stores of vitamin D (Weiler and colleagues, CMAJ 2005). This prompted Dr. Weiler’s research group at McGill University to test how much vitamin D is needed by newborn infants in Canada. They learned that 400 to 1200 international units of vitamin D given daily to healthy term born infants is enough to support healthy bone growth and mineral deposition (Gallo and colleagues, JAMA 2013). In conducting tests of bone health, they also learned that the amount of muscle was enhanced and fat reduced when infants had very good vitamin D stores. Vitamin D stores are reflected in the blood. Blood concentrations of a vitamin D form called 25-hydroxyvitamin D are used to establish if stores are in a healthy range. In the recent study published in Pediatric Obesity by Hazell et al, values above 75 nanomoles per litre of blood plasma were linked to lower amounts of body fat (~450 g) at 3 years of age. The 450 g difference is almost a pound of fat. This is a meaningful amount to young children where typical amounts of body fat are 10-times that equating to 4.5 kg (almost 10 pounds). Thus the lower fat is still in a healthy range.
Author Interviews, Genetic Research, PLoS, Vitamin D / 27.04.2016

MedicalResearch.com Interview with: [caption id="attachment_23795" align="alignleft" width="124"]Haidong Zhu, MD, PhD Associate Professor of Pediatrics Georgia Prevention Institute Medical College of Georgia Augusta University Dr. Haidong Zhu[/caption] Haidong Zhu, MD, PhD Associate Professor of Pediatrics Georgia Prevention Institute Medical College of Georgia Augusta University MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Zhu: Vitamin D plays an important role in a wide range of body functions beyond bone health. Vitamin D deficiency is associated with increased risk of cancer and cardiovascular disease. Vitamin D deficiency is common among darker skin individuals, particularly African-Americans, which could contribute to health disparity. We want to understand underlying molecular mechanism (i.e. global DNA methylation) for how vitamin D deficiency causes cancer, cardiovascular disease and impaired immune function. DNA methylation, a chemical modification to our genome, is one of the ways that our body adapts to the environment. Low rate of global DNA methylation is a common event in cancer, which may lead to disturbances in the genome, make the genome more vulnerable to environmental damage and increase disease risk. Our study shows that majority of black teens are vitamin D deficient and have a lower rate of global DNA methylation than white teens. We further demonstrate that vitamin D3 supplementation for 16 weeks increases global DNA methylation in black teens and young adults. Our study provides an important piece of evidence that vitamin D plays a role in epigenetic regulation in humans, which could be an underlying mechanism for vitamin D-deficiency related disease risk and health disparity.
Author Interviews, Cancer Research, PLoS, Vitamin D / 15.04.2016

MedicalResearch.com Interview with: Sharon L. McDonnell MPH GrassrootsHealth Encinitas, California Medical Research: What is the background for this study? What are the main findings? Response: Higher vitamin D levels in the blood have been associated with a lower risk of multiple cancer types including colorectal and breast. Using data from two study cohorts of women aged 55 years and older (N=2,304), we investigated the association between serum 25(OH)D concentration, the marker of vitamin D in the blood, and risk of all non-skin cancers combined across a broad range of 25(OH)D concentrations. We found that women with 25(OH)D concentrations ≥40 ng/ml had a 67% lower risk of cancer compared to women with concentrations <20 ng/ml. We also found that the greatest decrease in risk occurred between ~10-40 ng/ml. These findings suggest that increasing 25(OH)D concentrations to a minimum of 40 ng/ml could substantially reduce  cancer incidence and associated mortality in the population.
Author Interviews, Heart Disease, JACC, Vitamin D / 05.04.2016

MedicalResearch.com Interview with: [caption id="attachment_23091" align="alignleft" width="96"]Dr Klaus Witte MD, FRCP, FESC, FACC Associate Professor and Consultant Cardiologist Lead Clinician for Cardiology University of Leeds and Leeds Teaching Hospitals NHS Trust Dr. Klaus Witte[/caption] Dr Klaus Witte MD, FRCP, FESC, FACC Associate Professor and Consultant Cardiologist Lead Clinician for Cardiology University of Leeds and Leeds Teaching Hospitals NHS Trust  MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Witte: Chronic heart failure (CHF) is a condition of heart muscle weakness that despite optimal treatment often leaves patients with ongoing symptoms of breathlessness and fatigue. Vitamin D has a large number of effects in the body beyond its known effects on the skeleton. Patients with  Chronic heart failure are frequently deficient in vitamin D, but until now there were no data demonstrating a benefit from supplements. We conducted a randomised, placebo-controlled study of a non-calcium-based vitamin D supplement providing 4000IU or 100mcg per day of vitamin D3 (VINDICATE). Endpoints included 6-minute walk distance and cardiac function. We saw no improvement in 6 minute walk distance but a large and significant improvement in heart function (left ventricular ejection fraction) and heart size (left ventricular dimensions and volumes) after on year. We saw no significant adverse effects and the tablets were well tolerated.
Author Interviews, Endocrinology, Vitamin D / 03.04.2016

MedicalResearch.com-Interview with: [caption id="attachment_23111" align="alignleft" width="179"]Francisco Bandeira,M.D.,PhD.,F.A.C.E. Professor of Medicine and Chairman, Division of Endocrinology, Agamenon Magalhães Hospital, University of Pernambuco Medical School Dr. Francisco Bandeira[/caption] Francisco Bandeira,M.D.,PhD.,F.A.C.E. Professor of Medicine and Chairman, Division of Endocrinology, Agamenon Magalhães Hospital, University of Pernambuco Medical School MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Bandeira: We had the opportunity to evaluate a population with very high rates of sun exposure in daily life at a tropical region with abundant sunlight (UV index of 5 at 7 am and more than 10 at midday). We found that more exposure to the sun, less vitamin D deficiency, so nature “works”. But more sun exposure led to more tanned skins and despite these very high rates of sun exposure, most people were not able to achieve optimal blood levels of 25OHD (> 30 ng/ml).
Author Interviews, JAMA, Rheumatology, Vitamin D / 10.03.2016

MedicalResearch.com Interview with: [caption id="attachment_22335" align="alignleft" width="195"]Changhai Ding, MBBS, MMED, MD Australian Research Council Future Fellow Associate Director (International), Menzies Institute for Medical Research Professor, University of Tasmania, Australia Honorary Professor, University of Sydney, Australia Dr. Changhai Ding[/caption] Changhai Ding, MBBS, MMED, MD Australian Research Council Future Fellow Associate Director (International), Menzies Institute for Medical Research Professor,  University of Tasmania, Australia Honorary Professor, University of Sydney, Australia MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Ding: Vitamin D can reduce bone turnover and cartilage degradation, thus potentially preventing the development and progression of knee osteoarthritis. Observational studies suggest that vitamin D supplementation is associated with benefits for knee osteoarthritis, but current evidence from clinical trials is contradictory. We  conducted a randomised clinical trial in Hobart, Tasmania and Melbourne, Victoria in Australia. We randomly assigned 413 patients with symptomatic knee osteoarthritis and low 25-hydroxyvitamin D to receive monthly treatment with oral vitamin D3 (50,000 IU; n = 209) or an identical placebo (n = 204) for 2 years. Of 413 enrolled participants (average age, 63 years; 50 percent women), 340 (82 percent) completed the study. Vitamin D supplementation significantly increased blood 25-hydroxyvitamin D levels over 2 years compared with placebo treatment; however, vitamin D supplementation, compared with placebo, did not result in significant differences in change in MRI-measured tibial cartilage volume or a measure of knee pain over 2 years. There were also no significant differences in change of tibiofemoral cartilage defects or change in tibiofemoral bone marrow lesions. Post-hoc analyses indicated that vitamin D supplementation might improve knee physical function and reduce another measure of knee pain and increases in bone marrow lesion.
Author Interviews, Brigham & Women's - Harvard, JAMA, Vitamin D / 08.03.2016

MedicalResearch.com Interview with: Kassandra Munger, Sc.D. Harvard T.H. Chan School of Public Health MedicalResearch.com: What is the background for this study? Dr. Munger: Previous work has shown that adequate vitamin D nutrition is associated with a lower risk of multiple sclerosis (MS).  Results from studies examining whether adequate vitamin D exposure during early-life are also associated with a lower risk of MS have been mixed.  One study reported that daughters of mothers with high dietary vitamin D intake during their pregnancy had a reduced risk of multiple sclerosis, while two studies measuring 25-hydroxy vitamin D either in a blood sample from the pregnant mother or from a sample taken from the neonate, were not associated with future multiple sclerosis risk in the child.
Asthma, Author Interviews, JAMA, OBGYNE, Vitamin D / 27.01.2016

More on Asthma on MedicalResearch.com [caption id="attachment_19464" align="alignleft" width="133"]Professor of Pediatrics Hans Bisgaard, MD, DMSc Copenhagen Prospective Studies on Asthma in Childhood Herlev and Gentofte Hospital, University of Copenhagen, Denmark. Prof. Bisgaard[/caption] MedicalResearch.com Interview with: Hans Bisgaard, MD, DMSc Professor of Pediatrics The Faculty of Health Sciences University of Copenhagen Head of the Copenhagen Prospective Studies on Asthma in Childhood University  of Copenhagen and Naestved Hospital MedicalResearch: What is the background for this study? What are the main findings? Dr. Bisgaard: Vitamin D deficiency has become a common health problem in westernized societies, possibly caused by a more sedentary indoor lifestyle and decreased intake of vitamin D containing foods. Vitamin D possesses a range of immune regulatory properties, and it has been speculated that vitamin D deficiency during pregnancy may affect fetal immune programming and contribute to asthma pathogenesis. Asthma often begins in early childhood and is the most common chronic childhood disorder. Observational studies have suggested that increased dietary vitamin D intake during pregnancy may protect against wheezing in the offspring, but the preventive effect of vitamin D supplementation to pregnant women is unknown. In our double-blind, single-center, randomized clinical trial conducted within the Copenhagen Prospective Studies on Asthma in Childhood 2010 cohort we supplemented 2800 IU/d of vitamin D3 during the third trimester of pregnancy compared with 400 IU/d in the control group. Although the maternal supplementation did not result in a statistically significant reduction of risk of persistent wheeze in the offspring through age 3 years, the interpretation of the study is limited by a wide confidence interval that includes a clinically important protective effect.
Asthma, Author Interviews, Brigham & Women's - Harvard, JAMA, Vitamin D / 26.01.2016

[caption id="attachment_20929" align="alignleft" width="120"]Augusto A. Litonjua, MD, MPH Associate Professor Channing Division of Network Medicine and Division of Pulmonary and Critical Care Medicine Department of Medicine Brigham and Women's Hospital Harvard Medical School Boston, MA 02115 USA Dr. Augusto Litonjua[/caption] MedicalResearch.com Interview with: Augusto A. Litonjua, MD, MPH Associate Professor Channing Division of Network Medicine and Division of Pulmonary and Critical Care Medicine Department of Medicine Brigham and Women's Hospital Harvard Medical School Boston, MA 02115 USA  Medical Research: What is the background for this study? What are the main findings? Response: Vitamin D deficiency has been hypothesized to contribute to the asthma and allergy epidemic.  Vitamin D has been shown to affect lung development in utero. However, observational studies have shown mixed results when studying asthma development in young children. Since most asthma cases start out as wheezing illnesses in very young children, we hypothesized that vitamin D supplementation in pregnant mothers might prevent the development of asthma and wheezing illnesses in their offspring.  We randomly assigned 881 pregnant women at 10 to 18 weeks' gestation and at high risk of having children with asthma to receive daily 4,000 IU vitamin D plus a prenatal vitamin containing 400 IU vitamin D (n = 440), or a placebo plus a prenatal vitamin containing 400 IU vitamin D (n = 436). Eight hundred ten infants were born during the study period, and 806 were included in the analyses for the 3-year outcomes. The children born to mothers in the 4,400 IU group had a 20% reduction in the development of asthma or recurrent wheeze compared to the children born to mothers in the 400 IU group (24% vs 30%, respectively; an absolute reduction of 6%).  However, this reduction did not reach statistical significance (p=0.051).
Author Interviews, Johns Hopkins, Surgical Research, Vitamin D / 29.12.2015

[caption id="attachment_20339" align="alignleft" width="200"]Leigh A. Peterson, PhD, MHS Post-doctoral fellow Department of Surgery - Bayview Johns Hopkins School of Medicine Dr. Leigh Peterson[/caption] MedicalResearch.com Interview with: Leigh A. Peterson, PhD, MHS Post-doctoral fellow Department of Surgery - Bayview Johns Hopkins School of Medicine Medical Research: What is the background for this study? What are the main findings? Dr. Peterson: From our previous study published in Obesity Surgery earlier this year, we knew that vitamin D deficiency and insufficiency was very common in our bariatric surgery candidates (71.4% < 20 ng/ml and 92.9% < 30 ng/ml). We wanted to explore the effect of this deficiency on adverse outcomes after bariatric surgery such as wound healing, infection, and extended hospital stay. We turned to the Nationwide Inpatient Sample to answer this question, as it would contain enough surgeries to detect changes in even less frequent outcomes such as wound infection. But blood concentration of vitamin D is not available, so we used a traditional method to estimate group vitamin D status with season and geography. Vitamin D comes from the sun, so people have the most vitamin D in summer and in sunnier places. In 932,091 records of bariatric surgeries from 2001 to 2010, we saw that more adverse outcomes occurred during winter—January to March, the time of lowest vitamin D status—compared to summer or even spring or fall. Additionally, most adverse outcomes occurred in northern latitudes (≥ 37°N) compared to sunnier southern latitudes.
Author Interviews, Obstructive Sleep Apnea, Vitamin D / 24.12.2015

[caption id="attachment_20304" align="alignleft" width="133"]Ken M. Kunisaki , MD Associate Professor of Medicine Pulmonary, Allergy, Critical Care and Sleep Medicine University of Minnesota Dr. Kunisaki[/caption] MedicalResearch.com Interview with: Ken M. Kunisaki , MD Associate Professor of Medicine Pulmonary, Allergy, Critical Care and Sleep Medicine University of Minnesota  Medical Research: What is the background for this study? What are the main findings? Dr. Kunisaki : Obstructive sleep apnea (OSA) is a very common condition that is the result of recurrent complete or partial closure of the upper airway during sleep.  OSA leads to poor sleep quality and excessive daytime sleepiness. A previous study suggested that OSA is more common in the winter, but there were no vitamin D measurements in that study, which seemed potentially relevant since many people have lower vitamin D levels in the winter, due to less sunlight exposure in the winter.  Several studies have also shown that people with low vitamin D levels have worse muscle function.  Since muscles are partially responsible for keeping the upper airway open during sleep, we wondered whether people with low vitamin D levels might have weaker upper airway muscles and therefore be more prone to having OSA. In our study, we found that indeed, persons with OSA had lower vitamin D levels than those without OSA, but this was explained by obesity.  In other words, the low vitamin D levels seen in OSA patients is likely just a marker of obesity and not likely related to the presence or absence of OSA.
Author Interviews, Endocrinology, Exercise - Fitness, Heart Disease, Vitamin D / 03.11.2015

Dr Emad Al-Dujaili Reader in Biochemistry and Nutrition, Queen Margaret University Department of Health Science Queen Margaret UniversityMedicalResearch.com Interview with: Dr Emad Al-Dujaili Reader in Biochemistry and Nutrition, Queen Margaret University Department of Health Science Queen Margaret University Medical Research: What is the background for this study? What are the main findings? Dr. Al-Dujaili: Recent studies have implicated vitamin D deficiency as a risk factor for Cardiovascular disease and its deficiency is a potential biological predictor of increased rates of CVD. We have done 2 earlier studies investigating the effects of Vitamin D intake on Blood pressure and the stress hormone level cortisol and found that people taking the supplement of Vitamin D had reduced systolic and diastolic blood pressure compared to those who took the placebo. Vitamin D deficiency has also been associated with hypertension, obesity, diabetes mellitus and oxidative stress and reduced exercise performance. For instance, the Framingham offspring study proved that low levels of vitamin D are independently related to Cardiovascular disease incidence. In this placebo-controlled study, We have observed that people given 50ug of Vitamin D daily for 2 weeks showed a significantly reduced systolic and diastolic blood pressure, reduced urinary free cortisol (the hormone that produces stress and high blood pressure if its levels are high. Moreover, the distance cycled in 20 minutes significantly increased by 30% with slightly less efforts compared with that before Vitamin D supplement.
Author Interviews, Calcium, Kidney Disease, Kidney Stones, Supplements, Vitamin D / 20.10.2015

MedicalResearch.com Interview with: Christopher Loftus M.D. candidate Cleveland Clinic Lerner College of Medicine Medical Research: What is the background for this study? What are the main findings? Response: Most kidney stones are made, at least partially, of calcium composite. In a prospective study of nurses in the post-menopausal age, it was found that diets that contained high amounts of calcium were beneficial in preventing kidney stones in this population. In the gut, calcium can bind to oxalate which prevents it from being absorbed into the body and decreases the concentration of calcium in the urine. However there has been debate as to whether supplemental calcium (calcium pills) has the same beneficial effects as calcium in the diet. Supplemental calcium enters the gut in large quantities all at once so it may enter the blood stream in higher concentrations over smaller amounts of time. By the same token, vitamin D plays a role in the management and balance of calcium in the body and could potentially have an effect on stone formation as well.  It has also been debated whether vitamin D supplementation has major effect on patients who are known to be stone formers.  So we reviewed CT scans of patients and 24 hour urine collections (both male and female of adult age) who were known to have kidney stones and measured the growth of stones over a period of time. Our main findings were that supplementary calcium increased the rate of stone formation in these patients. We also found that vitamin D had a protective effect and patients taking only vitamin D had a slower rate of stone progression.
Author Interviews, Cognitive Issues, JAMA, Vitamin D / 15.09.2015

Joshua W. Miller, PhD Professor and Chair Dept. of Nutritional Sciences Rutgers The State University of New Jersey New Brunswick, NJ 08901 MedicalResearch.com Interview with: Joshua W. Miller, PhD Professor and Chair Dept. of Nutritional Sciences Rutgers The State University of New Jersey New Brunswick, NJ 08901  Medical Research: What is the background for this study? What are the main findings? Response: In recent years, there has been a growing scientific literature on the associations between low vitamin D status in older adults and risk of Alzheimer's disease/dementia, cognitive impairment and decline, and brain atrophy.  The vast majority of these studies have been conducted in predominantly white populations.  The relatively unique aspect of our study was that over half of the cohort consisted of African Americans and Hispanics.  What we found in our cohort (mean age ~75y, n=382 at baseline) was that participants with vitamin D deficiency (serum 25-hydroxyvitamin D <12 ng/ml) or vitamin D insufficiency (serum 25-hydroxyvitamin D between 12 ng/ml and <20 ng/ml) on average experienced faster rates of cognitive decline in episodic memory and executive function than participants with adequate vitamin D status.  Importantly, the association between vitamin D status and the rate of decline in cognitive function was independent of race/ethnicity.  However, the prevalence of low vitamin D status in the study participants was significantly higher in the African American and Hispanic participants compared with the White participants.  This is most likely due to the fact that darker skin pigmentation reduces the ability of sunlight to induce vitamin D synthesis in the skin.  It may also reflect differences in dietary intake of vitamin D and supplement use between the different race/ethnicity groups, though we did not assess this in our study.  Thus, though the rate of cognitive decline in African Americans and Hispanics does not seem to be more or less affected by low vitamin D status than in Whites, because African Americans and Hispanics have a higher prevalence of low vitamin D status, as subpopulations they may be more prone to rapid cognitive decline in old age.  Further studies addressing this possibility are needed.
Author Interviews, Hip Fractures, JAMA, Menopause, Osteoporosis, Vitamin D / 05.08.2015

MedicalResearch.com Interview with: Karen E. Hansen, M.D., M.S. Associate Professor of Medicine University of Wisconsin School of Medicine and Public Health Madison, WI 53705-2281 Medical Research: What is the background for this study? Dr. Hansen: The USPTF says to older community dwelling adults, "don't bother taking vitamin D", the Endocrine Society says "take 2,000-4,000 IU daily" and the Institute of Medicine gave an RDA of 600-800 IU daily. The Endocrine Society argues that optimal vitamin D levels are 30 ng/mL and higher, while the Institute of Medicine concludes that 20 ng/mL and higher indicates optimal vitamin D status. The disagreement between experts prompted my study. Medical Research: What are the main findings? Dr. Hansen: Among postmenopausal women whose vitamin D level was ~21 ng/mL at baseline, there was no benefit of high-dose or low-dose vitamin D, compared to placebo, on spine/hip/total body bone mineral density, muscle fitness by 5 sit to stand test or Timed Up and Go, or falls. We did see a small 1% increase in calcium absorption in the high-dose vitamin arm, but this small increase did not translate into clinically meaningful changes in bone density or muscle tests.
Author Interviews, CDC, Pediatrics, Vitamin D / 25.06.2015

Katherine Ahrens Ph.D. MPH National Center for Health Statistics Centers for Disease Control and Prevention Hyattsville, MDMedicalResearch.com Interview with: Katherine Ahrens Ph.D. MPH National Center for Health Statistics Centers for Disease Control and Prevention Hyattsville, MD Medical Research: What is the background for this study? Dr. Ahrens: In 2008, the American Academy of Pediatrics (AAP) revised their recommended minimum daily intake of vitamin D for infants and children to 400 IU. Medical Research: What are the main findings? Dr. Ahrens: Approximately one quarter of US infants aged 0 to 11 months met the 2008 AAP vitamin D recommendations on a given day in 2009 to 2012. Fewer than 1 in 5 breastfed infants met the vitamin D recommendations compared to nearly 1 in 3 non-breastfed infants.
Aging, Author Interviews, Exercise - Fitness, Frailty, JAMA, Vitamin D / 23.03.2015

MedicalResearch.com Interview with: Kirsti Uusi-Rasi, PhD, Adjunct Professor Senior Researcher UKK Institute for Health Promotion Research Tampere Finland Medical Research: What is the background for this study? What are the main findings? Dr. Kirsti Uusi-Rasi: Falls are the leading cause of unintentional injuries and fractures in older adults, head injuries and fractures being the most severe consequences. Therefore, falls prevention is important when trying to prevent injuries. There is strong high-quality evidence from previous studies that exercise that includes strength and balance training can reduce the risk of falling in older adults. However, there are also studies that have reported no benefit in reducing the actual incidence of falls. Effects of vitamin D have also been studied widely, and vitamin D is known to be vital for bone metabolism and health. However, results regarding effects on falls and fractures are inconsistent. Furthermore, persons with low vitamin D levels (serum 25OHD) have been associated with lower physical performance and greater decline in physical functioning, but clinical trials exploring the role of vitamin D in reducing falls and fractures and in improving physical functioning are inconclusive. Because there is hardly any evidence about exercise and vitamin D together, we investigated the separate and combined effects of multimodal exercise training and vitamin D supplementation in reducing falls and injurious falls among older women at risk for falling. We assigned 409 participants randomly to one of four groups with: 1)vitamin D 800 IU/day and exercise 2) placebo and exercise 3) vitamin D 800 IU/day without exercise 4) placebo without exercise. Exercise consisted of strength, balance, mobility and agility group training. At the end of two years, exercise seemed to be more effective in reducing injurious falls in this age group, with or without vitamin D. Exercise also improved physical functioning (strength, balance and mobility). In general, the training program was well tolerated with no severe adverse effects or injuries. Vitamin D helped maintain femoral neck BMD and increased trabecular bone density at the tibia. Our study also suggests that the current vitamin D recommendation (800 IU/d for older people) is adequate.
Author Interviews, Depression, Vitamin D / 18.03.2015

David C.R. Kerr Ph.D. Sch of Psychological Science Associate Professor College of Liberal Arts Oregon State UniversityMedicalResearch.com Interview with: David C.R. Kerr Ph.D. Sch of Psychological Science Associate Professor College of Liberal Arts Oregon State University Medical Research: What is the background for this study? What are the main findings? Dr. Kerr: Many people assume we already know that low levels of vitamin D contribute to depression, especially in winter. However, studies have not found consistent evidence for this, and most studies have focused on people in late life or with serious medical conditions. We focused on apparently healthy young women living in the Pacific Northwest. We found that women with low blood levels of vitamin D were more likely to report clinically significant depressive symptoms. This link existed even when we considered other factors that might explain both problems, such as diet, obesity, and time of year.