Author Interviews, Brigham & Women's - Harvard, Lancet, Pediatrics, Vitamin D / 05.12.2023

MedicalResearch.com Interview with: Dr Ganmaa Davaasambuu MD PhD Associate Professor Harvard T.H. Chan School of Public Health MedicalResearch.com: What is the background for this study? Response: The crucial role of vitamin D in facilitating calcium absorption from the diet and promoting calcium deposition in bones (known as 'mineralization') has been a long-established understanding. Furthermore, some observational studies have reported an association between low vitamin D levels and a heightened risk of bone fractures in children. This raised the possibility that vitamin D supplements could potentially play a role in decreasing fracture risk in children with initially low baseline levels. However, clinical trials assessing the causal link between low vitamin D status and reduced fracture risk were necessary, and such trials had not been conducted before. (more…)
Author Interviews, Brigham & Women's - Harvard, Endocrinology, Hip Fractures, NEJM, Osteoporosis, Vitamin D / 27.07.2022

MedicalResearch.com Interview with: Meryl S. LeBoff, MD Chief, Calcium and Bone SectionDirector of the Skeletal Health and Osteoporosis CenterDirector, Bone Density UnitDistinguished Chair in Skeletal Health and Osteoporosis Professor of Medicine, Harvard Medical School Endocrinology, Diabetes and Hypertension, Women's Health Brigham And Women's Hospital JoAnn E. Manson, MD, DrPH Professor, Epidemiology, Harvard T.H. Chan School Of Public Health Michael and Lee Bell Professor of Women's Health, Medicine, Harvard Medical School Chief, Preventive Medicine, Brigham And Women's Hospital Co-Director, Womens Health, Brigham And Women's Hospital   MedicalResearch.com:  What is the background for this study?  What are the main findings? Response: Osteoporosis is a major public health problem. Although supplemental vitamin D has been widely used to reduce the risk of fractures in the general population, studies of the effects of vitamin D on fractures, the most important bone health outcome, have been conflicting. Randomized controlled trials, the highest quality studies, from around the world have shown benefit, no effect, or even harm of supplemental vitamin D on risk of fractures. Some of the trials used bolus dosing, had small samples sizes or short study duration, and co-administered calcium. No large RCTS of this scale tested whether daily supplemental vitamin D (without co-administration with calcium) prevented fractures in the US population. To fill these knowledge gaps, we tested the hypothesis in this ancillary study to VITAL, whether daily supplemental vitamin D3 reduced the risk of incident total, non-spine and hip fractures in women and men in the US. (more…)
Author Interviews, Breast Cancer, Cancer Research, Race/Ethnic Diversity, Vitamin D / 26.04.2022

MedicalResearch.com Interview with: Katie M. O’Brien PhD Chronic Disease Epidemiology Group National Institute of Environmental Health Sciences MedicalResearch.com:  What is the background for this study?  What are the main findings? Response: Vitamin D may protect against breast cancer. Although women of color have lower average vitamin D levels than non-Hispanic White women, few studies have considered the role of race/ethnicity. In a sample of self-identified Black/African American and Hispanic/Latina women, we observed that vitamin D concentrations measured in blood were inversely associated with breast cancer, particularly among Latinas. These findings indicate that vitamin D may protect against breast cancer, including among racial/ethnic groups with low average circulating levels. (more…)
Author Interviews, JAMA, USPSTF, Vitamin D / 22.04.2021

MedicalResearch.com Interview with: Dr. Michael Silverstein M.D., M.P.H Professor of Pediatrics Director of the Division of General Academic Pediatrics Vice Chair of Research, Department of Pediatrics Boston University School of Medicine   MedicalResearch.com: What is the background for this study? What are the main findings? Response: Vitamin D is an important nutrient for keeping bones healthy, and it may also have a role in other aspects of good health. However, we do not have enough evidence to understand what levels of vitamin D people need to keep them healthy or what levels are too low. As a result, the Task Force determined there is not enough evidence to recommend for or against screening for vitamin D deficiency in adults who do not have signs or symptoms. It is our hope that with more research, we will be able to make a strong, evidence-based recommendation on screening for vitamin D deficiency in the future. (more…)
Author Interviews, Pediatrics, Vitamin D / 28.08.2020

MedicalResearch.com Interview with: Juan C. Celedón, MD, DrPH, ATSF Niels K. Jerne Professor of Pediatrics Professor of Medicine, Epidemiology and Human Genetics University of Pittsburgh Division Chief, Pulmonary Medicine UPMC Children’s Hospital of Pittsburgh Pittsburgh, PA 15224 MedicalResearch.com: What is the background for this study? Response: Findings from observational studies suggested that vitamin D levels below 30 ng/ml are associated with worse asthma and severe asthma attacks. Based on those results, we conducted a randomized, double-blind, placebo-controlled clinical trial of vitamin D3 supplementation to prevent severe asthma attacks in 192 high-risk children with asthma aged 6 to 16 years who had moderately low vitamin D levels and were taking low-dose inhaled steroids. (more…)
Asthma, Author Interviews, Brigham & Women's - Harvard, NEJM, Pediatrics, Vitamin D / 10.02.2020

MedicalResearch.com Interview with: Augusto A. Litonjua, M.D., M.P.H. Professor - Department of Pediatrics, Pulmonology Interim Chief - Department of Medicine , Pulmonary Diseases and Critical Care Professor - Department of Medicine , Pulmonary Diseases and Critical Care University of Rochester MedicalResearch.com: What is the background for this study? Response: Vitamin D deficiency and insufficiency is prevalent worldwide. Prior observational studies have shown that low vitamin D levels have been associated with the development of asthma. Animal studies have reported that antenatal vitamin D is important for lung development in utero. Thus, we conducted a randomized, double-blind, controlled trial of vitamin D supplementation in pregnant women to see if we could prevent the development of asthma and wheezing illnesses in young children. The initial report of the trial results showed that children born to mothers in the vitamin D supplementation arm had lower risks for developing either asthma or recurrent wheezing episodes over the first 3 years, but this was not statistically significant (p=0.051)(Litonjua et al. JAMA 2016). (more…)
Author Interviews, JAMA, Orthopedics, Vitamin D / 26.12.2019

MedicalResearch.com Interview with: Robert Clarke MD, FRCP, FFPH, FFPHI, MSc, DCH Professor of Epidemiology and Public Health Medicine Clinical Trial Service Unit (CTSU) Nuffield Department of Population Health University of Oxford MedicalResearch.com: What is the background for this study? Response: Approximately 1 in 2 women and 1 in 5 men aged 50 years or older will suffer from an osteoporotic fracture in their remaining lifetime. Hip fracture is the most serious type of osteoporotic fracture with an approximately 30% risk of death in the year following a hip fracture. Vitamin D is essential for optimal musculoskeletal health by promotion of calcium absorption, and mineralisation of osteoid tissue formation in bone and maintenance of muscle function. Low vitamin D status causes secondary hyperparathyroidism, bone loss and muscle weakness. Observational studies have reported that lower blood concentrations of vitamin D are associated with higher risks of falls and fractures. Combined supplementation with 800 IU/day vitamin D and 1200 mg/day calcium has been recommended for prevention of fractures in older adults living in institutions and in those with low vitamin D status. However, previous trials and meta-analyses of vitamin D alone, or in combination with calcium for prevention of fracture in either community-dwelling or general population settings reported conflicting results, with some reporting protective effects against fractures, but others demonstrated no beneficial effects. However, most of the previous trials had only limited power to detect differences in risk of fracture predicted by the observational studies, largely because of a combination of small sample size, relatively low equivalent daily doses of vitamin D, intermittent dosing regimens (>1 month), and short duration of follow-up. In addition, interpretation of the results of previous meta-analyses of such trials is complicated by use of variable inclusion criteria, inappropriate statistical methods, inclusion of multiple small trials with very few fracture events, in addition to failure to report achieved differences in blood 25(OH)D concentrations. We summarised the available evidence to guide clinical practice and future research, by conducting parallel meta-analyses of:
  • (i) observational studies of risks of fracture associated with prolonged differences in blood concentrations of 25(OH)D;
  • (ii) randomised trials of vitamin D alone versus placebo or no treatment for prevention of fracture; and
  • (iii) randomised trials of calcium and vitamin D versus placebo or no treatment for prevention of fracture.In addition, we reviewed the design of the ongoing randomised trials assessing the effects of higher doses of vitamin D alone or in combination with calcium for prevention of fracture.
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Author Interviews, Pediatrics, University of Michigan, Vitamin D / 21.08.2019

MedicalResearch.com Interview with: Eduardo Villamor, M.D., M.P.H., Dr.P.H. Professor, Epidemiology School of Public Health University of Michigan Ann Arbor, Michigan MedicalResearch.com: What is the background for this study? Response: Vitamin D deficiency has been related to adverse mental health outcomes, including depression and schizophrenia, in adults.  Some studies have suggested a potential role of vitamin D status prenatally on other neurodevelopmental outcomes in childhood.  However, few studies had extended into adolescence which is the life period when certain mental health issues that predict disease later in life, namely behavioral problems, first appear.  (more…)
Author Interviews, Dental Research, JAMA, OBGYNE, Pediatrics, Vitamin D / 06.08.2019

MedicalResearch.com Interview with: Hans Bisgaard, DMSc, MD Head of COPSAC, Professor Professor of Pediatrics, University of Copenhagen Founder and Head of the Copenhagen Prospective Studies on Asthma in Childhood; Gentofte Hospital, University of Copenhagen and Naestved Hospital MedicalResearch.com: What is the background for this study? Response: Enamel defects is a global health challenges affecting typically 1/3 of school children and more in some regions. It leads to break down of the teeth and caries later on. MedicalResearch.com: What are the main findings? Response: Supplementation with high-dose vitamin D compared to standard dose in the third pregnancy trimester in a mother child cohort of 588 pairs lead to a significant reduction of enamel defects. Enamel defects was found in 28% of children by age 6 after standard dose of vitamin D supplementation (400 i.u.), compared to 15% after 7-fold higher dose vitamin D.  (more…)
Annals Internal Medicine, Author Interviews, Supplements, Vitamin C, Vitamin D / 09.07.2019

MedicalResearch.com Interview with: Safi U. Khan, MD Department of Internal Medicine Robert Packer Hospital Sayre, PA 18840  MedicalResearch.com: What is the background for this study? Response: There is substantial body of observational data favoring use of vitamins, supplements and special diets for improving cardiovascular health. However, such type of data is limited by various biases. Randomized controlled trial (RCT) is considered gold standard to evaluate effects of a therapy.  (more…)
Author Interviews, Diabetes, Vitamin D / 09.06.2019

MedicalResearch.com Interview with: Anastassios G. Pittas, M.D MS Professor Co-Director, Diabetes and Lipid Center; Tufts Medical Center MedicalResearch.com: What is the background for this study? What are the main findings? Response: Observational studies have consistently reported an association between low blood vitamin D level and development of type 2 diabetes. However, whether vitamin D supplementation lowers risk of developing diabetes is not known. We designed and conducted the Vitamin D and diabetes (D2d) study to answer this question.  We randomized 2,423 people with prediabetes to 4,000 IU/day of vitamin D3 or placebo and followed them for new-onset diabetes with blood tests every 6 months for an average of 2.5 years. About 80% of participants had sufficient vitamin D level at baseline (25-hydroxyvitamin D level >= 20 ng/mL). The trial was designed to show a reduction of 25% or more in diabetes risk with vitamin D. The study was unable to show a reduction of 25% or more. At the end of the study, there was a 12% reduction in risk of developing diabetes with vitamin D, which missed statistical significance (hazard ration 0.88; 95% confidence interval 0.75 to 1.04). In a small subgroup of participants with vitamin D deficiency at baseline (25-hydroxyvitamin D level < 12 ng/mL) there was 62% reduction in risk of diabetes with vitamin D (hazard ration 0.38; 95% confidence interval 0.18 to 0.80). (more…)
Author Interviews, Cancer Research, JAMA, Vitamin D / 09.04.2019

MedicalResearch.com Interview with: Mitsuyoshi Urashima MD, PhD, MPH Professor of Molecular Epidemiology Jikei University School of Medicine Tokyo, JAPAN MedicalResearch.com: What is the background for this study?   Response: Serum levels of vitamin D, increase in response to exposure to sunlight, a vitamin D-rich diet, or vitamin D supplementation. In 1989, the risk of colon cancer was estimated to be 70% lower in people with serum vitamin D levels ≥ 20 ng/mL, compared with those < 20 ng/mL. In a cohort study, higher vitamin D levels were associated with lower total cancer incidence and lower total cancer mortality, particularly digestive system cancer mortality. However, because of the studies’ observational nature, whether lower levels of vitamin D is merely a precursor to relapse and death or causally related to shorter survival cannot be determined. To clarify this, a randomized, double-blind, placebo-controlled trial using vitamin D supplement was performed in patients with digestive tract cancer from esophagus to rectum; this is the first trial designed to evaluate the effect of vitamin D on survival of these patients.  (more…)
Asthma, Author Interviews, JAMA, OBGYNE, Pediatrics, Vitamin D / 12.03.2019

MedicalResearch.com Interview with: Bo Chawes, MD, PhD, DMSc Associate Professor C‌openhagen Prospective Studies on Asthma in Childhood H‌erlev and G‌entofte H‌ospital U‌niversity of C‌openhagen MedicalResearch.com: What is the background for this study? What are the main findings? Response: There has been a global surge in vitamin D deficiency happening in parallel with an increase in prevalence of childhood asthma, which suggests that low maternal vitamin D levels during pregnancy may increase asthma risk in the child. Due to that we conducted a randomized double-blinded controlled trial within the Danish COPSAC2010 cohort (www.copsac.com) of 7-fold (2,800 IU/d) vs. standard dose (400 IU/d) of vitamin D supplementation from pregnancy week 24 aiming to reduce offspring asthma risk. At age 3, we observed a non-significant 24% reduced risk of recurrent asthma-like symptoms, ie. recurrent wheeze, in the high-dose vitamin D group. In the current study, we followed 545 of the 581 children in the study till age 6, where an asthma diagnosis can be established and observed no effect of the high-dose vitamin D supplement on the child's risk of asthma.  (more…)
Author Interviews, Infections, Vitamin D / 10.02.2019

MedicalResearch.com Interview with: Professor Adrian Martineau, B Med Sci DTM&H MRCP PhD FRSB Clinical Professor of Respiratory Infection and Immunity Queen Mary University of London MedicalResearch.com: What is the background for this study? What are the main findings? Response: The World Health Organisation estimates that 10.0 million people developed active tuberculosis in 2017, and that 1.6 million people died of this disease. Multi-drug resistant (MDR) TB is caused by bacteria that are resistant to treatment with at least two of the most powerful first-line anti-TB drugs, causing around 500,000 cases and 150,000 deaths per year worldwide. Existing antibiotic treatments for MDR TB are lengthy, costly and often toxic due to their serious side effects. One novel approach to treating MDR TB is to complement antibiotic treatment by using therapies that boost the immune system’s ability to kill TB bacteria. Vitamin D – the sunshine vitamin – is known to help white blood cells to make natural antibiotic substances (antimicrobial peptides) that can punch holes in the cell membranes of TB bacteria. Several clinical trials have investigated the effects of adding vitamin D to antibiotic treatment for TB. In this study we pooled data from 8 of these studies (1850 participants) and analysed them to see if some TB patients benefited more from adding vitamin D to their treatment regimen than others. We found that vitamin D accelerated clearance of TB bacteria from the lungs of patients who had MDR TB; this benefit was not seen in patients who had ‘standard’ drug-sensitive TB. (more…)
Author Interviews, Mineral Metabolism, Vitamin D / 09.10.2018

MedicalResearch.com Interview with: "MaxMedica D-vitamin" by Midsona Sverige AB is licensed under CC BY 2.0Dr Mark J Bolland PhD Bone and Joint Research Group Department of Medicine University of Auckland New Zealand MedicalResearch.com: What is the background for this study? Response: Vitamin D supplements have long been recommended for older people to treat or prevent osteoporosis. Early evidence suggested vitamin D supplements might have benefits for musculoskeletal health, but more recent systematic reviews have reported no effect of vitamin D supplementation on fractures, falls or bone mineral density. Some authors have suggested that inadequate vitamin D doses might explain these null results. (more…)
Author Interviews, Colon Cancer, JNCI, NIH, Vitamin D / 09.07.2018

MedicalResearch.com Interview with: Stephanie J. Weinstein, M.S., Ph.D.  Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics National Cancer Institute, NIH   MedicalResearch.com: What is the background for this study?   Response: Vitamin D, known for its role in maintaining bone health, is hypothesized to lower colorectal cancer risk via several pathways related to cell growth and regulation. Previous prospective studies have reported inconsistent results for whether higher concentrations of circulating 25-hydroxyvitamin D, the accepted measure of vitamin D status, are linked to lower risk of colorectal cancer. The few randomized clinical trials of vitamin D supplementation and colorectal cancer completed thus far have not shown an effect; but study size, relatively short supplementation duration, and only moderate compliance may have contributed to their null findings. To address inconsistencies in prior studies on vitamin D, and to investigate associations in population subgroups, we harmonized and analyzed participant-level data from over 5,700 colorectal cancer cases who had blood collected before colorectal cancer diagnosis, and 7,100 matched cancer-free controls. Study participants were drawn from 17 prospective cohorts from the United States, Europe, and Asia and were followed for an average of 5.5 years (range: 1 – 25 years). We used a single, widely accepted assay and laboratory for new vitamin D measurements and calibrated existing vitamin D measurements. In the past, substantial differences between assays made it difficult to integrate vitamin D data from different studies. Our novel calibration approach enabled us to explore risk systematically over the broad range of vitamin D levels seen internationally.  (more…)
Author Interviews, Breast Cancer, Cancer Research, PLoS, Vitamin D / 22.06.2018

MedicalResearch.com Interview with: Cedric F. Garland, Dr.P.H., F.A.C.E. Adjunct Professor Division of Epidemiology Department of Family Medicine and Public Health University of California San Diego La Jolla, California 92093-0620 MedicalResearch.com: What is the background for this study? Response: Studies mapping death rates from female breast cancer in the US, the former USSR and Canada by Drs. Edward Gorham, and Frank and Cedric Garland revealed for the first time in history that death rates from breast cancer tracked latitude where people lived. The rates were highest in the least sunny northern tier of states, lowest in the sunny southwest. This led these scientists to be the first to theorize that vitamin D prevents breast cancer” said study first author Sharon McDonnell. (more…)
Author Interviews, BMJ, Global Health, Pediatrics, Vitamin D, Weight Research / 04.05.2018

MedicalResearch.com Interview with: Dr Javeria Saleem PhD Department of Public Health, Institute of Social and Cultural Studies, University of the Punjab, Lahore, Pakistan Centre for Primary Care and Public Health, Blizard Institute, Barts and The London School of Medicine and Dentistry Queen Mary University of London London, United Kingdom MedicalResearch.com: What is the background for this study? What are the main findings? Response: Severe acute malnutrition is the most extreme and visible form of undernutrition. Affected children have very low weight for their height and severe muscle wasting; they may also have swollen feet, face and limbs. Around 20 million children suffer from severe acute malnutrition worldwide of whom an estimated 1.4 million live in Pakistan. The condition is a major cause of death in children under 5 in Asia and Africa. The standard treatment is to give a high-energy, micronutrient enhanced paste called ready-to-use therapeutic food (RUTF). Vitamin D deficiency has been reported to be a risk factor for severe wasting in children with severe acute malnutrition Ready-to-use therapeutic food contains relatively modest amounts of vitamin D. However, the effects of adding high-dose vitamin D to this standard treatment have not previously been evaluated. We therefore did a clinical trial to assess whether high-dose vitamin D hastened recovery in 185 children aged 6-58 months who were receiving standard treatment for severe acute malnutrition in Southern Punjab, Pakistan. The 93 children in the active arm of the study received two doses of 5 mg vitamin D by mouth, while the 92 children in the control arm received placebo (a dummy medicine containing no vitamin D). Our findings were very striking: after 2 months of treatment, the children who received high-dose vitamin D in addition to standard therapy had significantly better weight gain, and significantly better motor and language development, than those who received standard treatment alone. (more…)
Accidents & Violence, Author Interviews, Geriatrics, Vitamin D / 25.04.2018

MedicalResearch.com Interview with: Dr. Alex Krist, M.D., M.P.H. Dr. Krist is is a professor of family medicine and population health at Virginia Commonwealth University and active clinician and teacher at the Fairfax Family Practice residency. What is the background for these recommendation statements? What are the main findings? Response: Falls are the leading cause of injuries in adults age 65 and older and can lead to serious disability and even death. Bone fractures—which may result from a fall—can also cause serious disability and death in older adults. The U.S. Preventive Services Task Force looked into the most recent evidence on the best ways to prevent falls and fractures in older adults. We found that clinicians should recommend exercise or physical therapy to help prevent falls by older adults who live at home and are at higher risk for falling. Additionally, we concluded that taking a low dose of vitamin D and calcium does not help prevent fractures due to osteoporosis, but we don’t know if taking a higher dose is effective or not, so we are calling for more research. (more…)
Author Interviews, Geriatrics, Nutrition, Vitamin C, Vitamin D / 18.12.2017

MedicalResearch.com Interview with: “vitamins” by Colin Mutchler is licensed under CC BY 2.0Priv.-Doz. Dr. Barbara Thorand  Helmholtz Zentrum München German Research Center for Environmental Health Institute of Epidemiology II Neuherberg, Germany  MedicalResearch.com: What is the background for this study? Response: Micronutrients, which include vitamins, minerals (e.g. calcium) and trace elements (e.g. iron), are essential nutrients that are required in minute amounts by the organism for proper growth and good health. Results from the last German National Nutrition Survey (NVS II)* uncovered a high prevalence of insufficient dietary intake of micronutrients in older adults aged 65 years and over in Germany. By means of blood analyses, our study has confirmed these critical results. This is a highly relevant issue, particularly in light of our growing aging population and the high societal relevance of successful healthy aging. *Max Rubner-Institut: Nationale Verzehrsstudie II, Ergebnisbericht Teil 2 (2008). Die Bundesweite Befragung zur Ernährung von Jugendlichen und Erwachsenen. (more…)
Asthma, Author Interviews, BMJ, Vitamin D / 04.10.2017

MedicalResearch.com Interview with: David Jolliffe, PhD Centre for Primary Care and Public Health Blizard Institute Barts and the London School of Medicine and Dentistry London MedicalResearch.com: What is the background for this study? Response: Asthma affects more than 300 million people worldwide and is estimated to cause almost 400,000 deaths annually. Asthma deaths arise primarily during episodes of acute worsening of symptoms, known as attacks or ‘exacerbations’, which are commonly triggered by viral upper respiratory infections. Vitamin D is thought to protect against such attacks by boosting immune responses to respiratory viruses and dampening down harmful airway inflammation. Several clinical trials have tested whether vitamin D supplementation might protect against asthma attacks, but individually their results are inconclusive. In the current study, we pooled raw data from 955 asthma patients who took part in 7 separate trials, which allowed us to answer two questions: 1, Does vitamin D protects against asthma attacks overall, when data from all trials are pooled? 2, Do people who have lower vitamin D levels to start with particularly benefit from supplementation? (more…)
Author Interviews, Infections, JAMA, Pediatrics, Respiratory, Vitamin D / 18.07.2017

MedicalResearch.com Interview with: Jonathon Maguire MD MSc FRCPC Scientist, Li Ka Shing Knowledge Institute Staff Pediatrician, Department of Pediatrics, St. Michael’s Hospital MedicalResearch.com: What is the background for this study? What are the main findings? Response: Vitamin D has been hypothesized as being protective of seasonal viral upper respiratory tract infections.  In this randomized clinical trial, high dose wintertime vitamin D supplementation (2000 IU/day) was compared with standard-dose vitamin D supplementation (400 IU/day) among 703 children.  The number of laboratory confirmed viral upper respiratory tract infections was not statistically different between groups. (more…)
Allergies, Asthma, Author Interviews, Dermatology, PLoS, Vitamin D / 10.05.2017

MedicalResearch.com Interview with: Brent Richards, MD, MSc Associate Professor of Medicine William Dawson Scholar / FRQS Clinical Research Scholar Departments of Medicine, Human Genetics, Epidemiology and Biostatistics McGill University Senior Lecturer, King's College London (Honorary) MedicalResearch.com: What is the background for this study? What are the main findings? Response: Some previous epidemiological studies have suggested that low vitamin D levels are associated with increased rates of asthma, atopic dermatitis—an itchy inflammation of the skin—and elevated levels of IgE, an immune molecule linked to atopic disease (allergies). In our study, we looked at genetic and health data on more than 100,000 individuals from previous large studies to determine whether genetic alterations that are associated with vitamin D levels predispose people to the aforementioned conditions. We found no statistically significant difference between rates of asthma (including childhood-onset asthma), atopic dermatitis, or IgE levels in people with and without any of the four genetic changes associated with lower levels of 25-hydroxyvitamin D, the form of vitamin D routinely measured in the blood. (more…)
Author Interviews, Heart Disease, JAMA, Vitamin D / 13.04.2017

MedicalResearch.com Interview with: Robert Scragg, MBBS, PhD School of Population Health The University of Auckland Auckland New Zealand MedicalResearch.com: What is the background for this study? What are the main findings? Response: Interest in a possible role for vitamin D deficiency as a risk factor for cardiovascular disease was stimulated by studies showing a seasonal variation in cardiovascular disease, which is much higher in winter, when body levels of vitamin D are low, than in summer. Main findings are that bolus monthly doses of vitamin D supplementation do not prevent against cardiovascular disease, even in people with low levels of vitamin D. (more…)
Author Interviews, Gastrointestinal Disease, Pediatrics, PLoS, Vitamin D / 10.04.2017

MedicalResearch.com Interview with: Benjamin Udoka Nwosu, MD, FAAP Associate Professor of Pediatrics Division of Endocrinology University of Massachusetts Medical School Worcester, Massachusetts MedicalResearch.com: What is the background for this study? What are the main findings? Response: Vitamin D deficiency has been reported in various gastrointestinal disorders but the vitamin D status of children and adolescents with irritable bowel syndrome (IBS) has not been previously characterized. Secondly, the vitamin D status in IBS has not been compared to those of other malabsorption syndromes such as irritable bowel syndrome, lactose intolerance, and celiac disease. (more…)
Author Interviews, Cancer Research, JAMA, Vitamin D / 27.03.2017

MedicalResearch.com Interview with: Joan M. Lappe, Ph.D., R.N., F.A.A.N. Associate Dean for Research, College of Nursing Criss/Beirne Professor of Nursing Professor of Medicine Creighton University Omaha NE 68131 MedicalResearch.com: What is the background for this study? What are the main findings?
  • Numerous observational studies show that higher vitamin D intake and serum 25, hydroxyvitamin D [25(OH)D], the functional indicator of vitamin D status, are associated with lower incidence of cancer.
  • However, the scientific fields consider randomized clinical trials (RCT) as a gold standard for testing new interventions for prevention and treatment of disease. In the only RCT of cancer and vitamin D to date with cancer as a primary outcome, the Women’s Health Initiative, postmenopausal women randomly assigned to vitamin D3400 IU/day and calcium 1000 mg/day showed no difference from those assigned to placebo in colorectal cancer incidence. One criticism of that study was that the vitamin D intervention was low, only 400 international units (IU) per day.
  • In our study we found that, in healthy women ages 55 and older with a mean baseline serum 25(OH)D of 33 ng/mL, supplementation with 2000 IU/day of vitamin D3and 1500 mg/day of calcium for four years, compared with placebo, decreased all-type cancer incidence by about 30%, but this did not reach statistical significance. (p value =0.057 and for statistical significance, the p value would need to be less than 0.05.)
  • In a secondary analysis, we re-analyzed the data excluding cancers that developed during the first year of study and were likely present but not diagnosed upon study enrollment. The findings here were that vitamin D and calcium did significantly decrease cancer risk by about 35%.
  • In another secondary analyses, we combined all of the serum 25(OH)D values to determine if higher levels were associated with lower cancer incidence. Here, higher serum 25(OH)D was significantly associated with lower cancer incidence. Persons with serum 25(OH)D of 55 ng/mL had a 35% lower risk of cancer than persons with serum 25(OH)D of 30 ng/mL.  This is especially interesting since current recommendations for sufficient serum 25(OH)D levels are 20 ng/mL (the National Academy of Medicine) and 30 ng/mL (the Endocrine Society).
  • Note that serum 25(OH)D is a better predictor of cancer development than assigning persons to supplement groups. Serum 25(OH)D takes into account poor compliance of the active supplement group with taking supplements, personal use of supplements by the placebo group, dietary vitamin D intake, sunlight exposure, and the variation among persons in absorption and metabolism of the vitamin D supplement.
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Author Interviews, Vitamin D / 15.03.2017

MedicalResearch.com Interview with: 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). (more…)
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. (more…)
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. (more…)