Compensation for the interracial variance in the cutaneous synthesis of vitamin D

J Lab Clin Med. 1995 Nov;126(5):452-7.

Abstract

We investigated the homeostatic compensation for the lower cutaneous synthesis of vitamin D in heavily melanized persons. Vitamin D2 (50,000 IU) was administered in a single oral dose to 24 young adults, 12 blacks and 12 whites, matched for age, gender, and socioeconomic status. We also included a group of eight healthy elderly white adults as representatives of a population with a nonracial mechanism for decreased cutaneous vitamin D synthesis. Plasma determinants were performed under basal conditions and at 6, 10, and 24 hours after vitamin D intake. Basal 25-hydroxyvitamin D (25-OH-D) levels were significantly lower in blacks (12.5 +/- 2.2 ng/ml (mean +/- SEM)) and in elderly whites (19.2 +/- 1.9 ng/ml), compared with young whites (30.2 +/- 3.0 ng/ml (p < 0.0001)); levels of basal 1,25-dihydroxyvitamin D (1,25(OH)2 -D) did not differ between groups. The vitamin D blood curve was similar between groups after the oral vitamin D2 load. Increases in 25-OH-D were 91.7 +/- 15.9% in blacks, 18.8 +/- 5.2% in young whites, and 28.6 +/- 6.9 in elderly whites; 1,25(OH)2-D levels increased slightly and did not differ between groups, although in blacks the change over time was significant (p < 0.05). As a whole, the study populations exhibited a strong relation between basal and peak 25-OH-D (r = -0.80; p < 0.001). Levels of intact parathyroid hormone and serum calcium of blacks and young whites did not differ within or between groups throughout the test.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Oral
  • Adult
  • African Continental Ancestry Group*
  • Aged
  • Aged, 80 and over
  • Calcifediol / blood
  • Calcitriol / blood
  • Calcium / blood
  • Cholecalciferol / blood
  • Ergocalciferols / administration & dosage
  • Ergocalciferols / blood
  • European Continental Ancestry Group*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Parathyroid Hormone / blood
  • Skin / metabolism*
  • Skin Pigmentation / physiology*
  • Vitamin D / biosynthesis*
  • Vitamin D / blood

Substances

  • Ergocalciferols
  • Parathyroid Hormone
  • Vitamin D
  • Cholecalciferol
  • Calcitriol
  • Calcifediol
  • Calcium