Is There Pandemic Vitamin D Deficiency in the Black Population? A Review of Evidence

ABSTRACT

Although 1,25-dihydroxyvitamin D [1,25(OH)₂D] is the biologically active form of vitamin D, measurement of the total serum 25-hydroxyvitamin D [25(OH)D] level is the gold standard used to define vitamin D status. Currently, it is widely accepted that serum 25 (OH) D levels below 20 ng/ml defines vitamin D deficiency. According to this definition, there appears to be pandemic vitamin D deficiency in the Black population. However, there is no evidence of higher-than-normal rates of common complications and symptomology of true vitamin D deficiency in the Black population. What is going on? We researched the MEDLINE databases to find studies, from 1967 to present, that directly compare between Blacks and Caucasians the following: serum vitamin D level, serum calcium level, serum parathyroid hormone level, bone mineral density and health, and non-skeletal risks associated with vitamin D deficiency. The available studies consistently show that Blacks tend to have serum 25(OH)D levels in the deficient range while their serum 1,25(OH)₂D level is similar to, if not even slightly higher than that of Caucasians, and that the serum Ca²⁺ level in Blacks is virtually identical to that in Caucasians. Therefore, it appears that the serum 25(OH)D level is not the best marker of vitamin D sufficiency or deficiency in Blacks. In the future, clinical evaluation of the vitamin D status in the Black population needs to consider other serum biomarkers such as 1,25(OH)₂D and/or bioavailable 25(OH)D.

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