Clinical points on VITAMIN D supplements in adults
Recent data will bring more clarity about the role of vitamin d supplements in adults. The year 2019 wasn't good for the sunshine vitamin (vitamin D). That's because randomized trials showed that vitamin D supplements don't benefit heart disease, various types of cancer, or diabetes, despite years of promising observational data. Plus most evidence suggests vitamin D supplements don't reduce falls in seniors and there's no good evidence for boosting energy.
Save vitamin D screening for patients with osteoporosis or at risk of low levels due to chronic kidney disease, malabsorption, etc. Advise getting enough vitamin D to maintain bone health from food and supplements. But don't rely on it for other benefits. And don't recommend sun exposure without sunscreen as a way to increase vitamin D levels due to concerns of skin cancer risk.
In general, suggest getting 15 mcg/day (600 IU) for adults up to age 70 and 20 to 25 mcg/day (800 to 1000 IU) for older patients. Note: Convert vitamin D from IU to micrograms by dividing by 40. For example, 1,000 IU vitamin D will now be labeled as 25 mcg.
- Labeling changes for some vitamins will lead to unfamiliar doses on home medication lists.
- Updated supplement labels are already popping up on shelves and all products must have the new labeling from January 2021. One big change is with vitamin D supplements. We're used to seeing doses in international units (IU), now they'll be in micrograms.
- Think of this as a good thing, since "IU" is an error-prone abbreviation that can be misread as 10 (ten) or IV (intravenous). Convert vitamin D from IU to micrograms by dividing by 40. For example, 1000 IU vitamin D will now be labeled as 25 mcg.
- Expect some vit D labels to keep BOTH units to limit confusion, but don't count on all manufacturers to do this.
Educate about vitamin D in foods. For example, there's about 1 mcg (40 IU) in an egg yolk, 2 to 3 mcg (80 to 120 IU) in a cup of fortified orange juice or milk and 12 mcg (480 IU) in 3 oz of salmon. But many adults may need a supplement if food isn't enough. Vitamin D3 (cholecalciferol) may be more potent than D2 (ergocalciferol). But explain that either can be used for bone health.
Discourage routine use of high doses, especially 100 mcg (4,000 IU)/day and higher. Mounting data suggest these lack benefit and may LOWER bone density, possibly by stimulating bone resorption. Recommend saving vitamin D 1.25 mg (50,000 IU) once WEEKLY for 8 weeks as an option to treat deficiency, such as a level below 20 ng/mL.
References
- LeFevre ML, LeFevre NM. Vitamin D Screening and Supplementation in Community-Dwelling Adults: Common Questions and Answers. Am Fam Physician. 2018;97(4):254-260.
- Manson JE, Cook NR, Lee IM, et al. Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. N Engl J Med. 2019;380(1):33-44.
- Barbarawi M, Kheiri B, Zayed Y, et al. Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 83 000 Individuals in 21 Randomized Clinical Trials: A Meta-analysis. JAMA Cardiol. 2019;4(8):765-776.
- Burt LA, Billington EO, Rose MS, Raymond DA, Hanley DA, Boyd SK. Effect of High-Dose Vitamin D Supplementation on Volumetric Bone Density and Bone Strength: A Randomized Clinical Trial. JAMA. 2019;322(8):736-745.
- Dietary Reference Intakes for Calcium and Vitamin D Health Effects of Vitamin D and Calcium Intake [online]. Available at: https://www.nap.edu/resource/13050/Vitamin-D-and-Calcium-2010-Report-Brief.pdf
