To D or Not to D…That Is the Question

New guidelines will reignite controversy over when to recommend vitamin D supplementation in adults and whether to check levels.

About 41% of people in the US have low vitamin D levels...due to diet deficiency, lack of sun exposure, etc.

While data link low vitamin D levels to conditions such as heart disease, dementia, and various types of cancer, vitamin D supplements don’t seem to benefit these patients.

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That’s why new guidelines aim to tease out which patients may benefit from vitamin D supplementation or screening.

Don’t generally recommend vitamin D supplements for healthy adults under age 75...any benefit is unlikely to be clinically significant.

Advise saving vitamin D levels for patients with hypocalcemia or at risk of low vitamin D due to chronic kidney disease, malabsorption, etc.

Keep in mind, guidelines now suggest empiric vitamin D for adults age 75 years and older, adults with prediabetes, and pregnant patients.

But be aware of nuances with the evidence behind these recommendations...to help guide decisions and provide perspective.

For example, the benefit for patients 75 or older is small.

Explain that an analysis of several studies shows that taking about 900 IU (22.5 mcg) of vitamin D daily for 2 years leads to 6 fewer deaths per 1,000 people versus no supplementation...but doesn’t reduce fractures.

If these older patients want to take vitamin D, stick with lower daily dosing (800 to 1,000 IU) in place of higher weekly dosing.

In patients with prediabetes, pooled data show that the jury’s still out over whether taking vitamin D reduces the risk of developing diabetes or lowers A1c. Plus this is with higher doses...about 3,500 IU daily.

For these patients, continue to emphasize lifestyle changes with proven outcomes...such as a healthy diet and regular exercise...instead of vitamin D supplementation.

And for most pregnant patients, continue to recommend a typical prenatal vitamin.

Explain that new recommendations for pregnant patients are based on studies with results that may be due to chance...and most were conducted in countries where the standard of care differs from the US.

Use our resource, Calcium and Vitamin D, for more details about dosing and vitamin D2 versus D3.

Key References

  • Demay MB, Pittas AG, Bikle DD, et al. Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2024 Jul 12;109(8):1907-1947.
  • Cui A, Xiao P, Ma Y, et al. Prevalence, trend, and predictor analyses of vitamin D deficiency in the US population, 2001-2018. Front Nutr. 2022 Oct 3;9:965376.
  • Michael W, Couture AD, Swedlund M, et al. An Evidence-Based Review of Vitamin D for Common and High-Mortality Conditions. J Am Board Fam Med. 2022 Dec 23;35(6):1217-1229.
Pharmacist's Letter. October 2024, No. 401003



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