Vitamin D Supplementation: White-Black Young Women May Need Different Doses Interview with: Christopher J Gallagher MD

Bone Metabolism Unit, Creighton University Medical Center, Omaha, Nebraska What are the main findings of the study?

Dr. Gallagher: Vitamin D 400 IU daily will meet the RDA ( Recommended Dietary Allowance for 97.5% of population) for young white women age 25-45 years.

Black women may need more- 800-1600 IU, however,the number of black women in study was small and this dose needs confirmation. This data is based on exceeding a serum 25 hydroxyvitamin D level of 20ng/ml ( 50nmol/l) Were any of the findings unexpected?

Dr. Gallagher: No unexpected findings. For comparison we found that in older white and black women the RDA for vitamin D is 600-800 daily . This means that 97.5%of women meet the target with that dose, however 90% will meet the RDA with 400IU daily.

So there is not a large difference between young and old women. What should clinicians and patients take away from your report?

Dr. Gallagher: To meet the RDA for vitamin D a minimum of 400IU and no more than 800IU daily is needed. There is no need to measure serum 25OHD in normal people. I recommend vitamin D 400 IU daily. If you want to check a 25hydroxyvitamin D level I would do it in late winter(March).

If women really avoid sun exposure and use sunscreen then I would give 800IU daily What recommendations do you have for future research as a result of this study?

Dr. Gallagher: This study should be done in other ethnic groups,e.g. Asians ,Hispanics and not forgetting men.


Vitamin D supplementation in young Caucasian and African American women.

Gallagher CJ, Jindal PS, Smith LM.

Bone Metabolism Unit, Creighton University Medical Center, Omaha, Nebraska.
J Bone Miner Res. 2013 Jun 12. doi: 10.1002/jbmr.2010. [Epub ahead of print

Last Updated on August 6, 2013 by Marie Benz MD FAAD