Vitamin D deficiency in cord plasma from multiethnic subjects living in the tropics.

Halm BM, Lai JF, Pagano I, Cooney W, Soon RA, Franke AA.

Journal of the American College of Nutrition · 2013

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Abstract

Background Vitamin D deficiency is commonly reported in high-latitude areas and in dark-pigmented individuals. However, nothing is known about vitamin D in cord blood from multiethnic subjects living in the tropics. Objective Our study objective was to determine the prevalence of vitamin D deficiency in summer and winter in cord blood from multiethnic individuals in Hawai'i where sufficient sun irradiance occurs year-round for cutaneous vitamin D production. Methods 25-Hydroxyvitamin D (25(OH)D) levels were quantified by enzyme immunoassay in 100 cord plasma samples from apparently healthy full-term newborns and their mothers. Stratification was performed by birth season and ethnicity. Results Mean 25(OH)D levels were 24.5 ng/mL (9.1-68.3 ng/mL). Overall, 28% of samples were vitamin D deficient ( Conclusion Our results suggest that prenatal supplement recommendations of 400 IU vitamin D/day do not protect against vitamin D deficiency, even in subjects living in the tropics where ample sun irradiance exists for cutaneous vitamin D synthesis. The high prevalence of vitamin D deficiency we observed emphasizes the necessity for regular 25(OH)D monitoring, particularly during pregnancy and lactation, in dark-pigmented individuals, and during winter months.