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On average, black Americans have lower vitamin D levels than do white Americans. In this double-blind randomized trial of 260 healthy black American women (age, ≥60) with baseline 25-hydroxyvitamin D [25(OH)D] levels between 8 ng/mL and 26 ng/mL, researchers examined the effects of vitamin D supplementation on bone density and cognition. Women received either vitamin D3 (adjusted to achieve serum 25(OH)D levels of >30 ng/mL) or placebo for 3 years. The average vitamin D3 dose was 3500 IU daily.
Mean 25(OH)D level was 22 ng/mL at baseline; it increased to 47 ng/mL in the supplemented group and remained unchanged in the placebo group. During the 3-year study, bone-mineral density decreased modestly at the hip and distal radius in both groups, with no differences between groups.
Cognition was assessed using the Mini-Mental State Examination (MMSE). At baseline, nearly all participants had scores between 27 and 30 (maximum score, 30). At 3 years, mean scores had increased slightly in both groups, with no differences between groups.
Aloia J et al. Vitamin D supplementation in elderly black women does not prevent bone loss: A randomized controlled trial. J Bone Miner Res 2018 Nov; 33:1916. (https://doi.org/10.1002/jbmr.3521)
Owusu JE et al. Cognition and vitamin D in older African-American women— Physical performance and osteoporosis prevention with vitamin D in older African Americans trial and dementia. J Am Geriatr Soc 2019 Jan; 67:81. (https://doi.org/10.1111/jgs.15607)
Comment
In healthy older black women, vitamin D supplementation did not prevent bone loss compared with placebo, even though baseline vitamin D levels were in a range that was considered to be deficient or “insufficient” by some authorities. In addition, supplementation had no obvious effect on cognition, although the MMSE is a blunt instrument for detecting subtle cognitive decline, and there was little room for improvement in this healthy cohort.