TY - JOUR
T1 - Serial ultraviolet b exposure and serum 25 hydroxy vitamin d response in young adult american blacks and whites
T2 - No racial differences
AU - Brazerol, William F.
AU - McPhee, Andrew
AU - Mimouni, Francis
AU - Specker, Bonny L.
AU - Tsang, Reginald C.
N1 - Funding Information:
The endogenous production of vitamin D3 requires the interaction of ultraviolet B (UVB) radiation (wavelength 280-315 nm) with vitamin D3precursors in the skin. The major site of production of vitamin D3 is the basal layer of the epidermis, where 7-dehydrocholesterol is converted to previtamin D3during UVB exposure. Previtamin D3in turn undergoes a temperature-dependent isomerization to vita min D3. As such, the skin may be viewed as a photoendocrine organ [1,2]. In vitamin D unsupplemented populations, this organ represents the major source of vitamin D. From in vitro and in vivo studies, it has been proposed that skin pigmentation, by limiting UVB penetrance to the basal skin layer, may be a determining factor for the vitamin D response toagivendoseofUVB[3-5].Assuch,dark skin pigmentation combined with limited UVB exposure and marginal dietary vitamin D, are Supported in part by NIH Perinatal Research Training Grant, NIH Clinical Research Center Grant RR 00068, NIH HD-11725, NIH HD-20748 Perinatal Emphasis Research Center (PERO, the Children's Hospital Research Foundation, and Procter and Gamble Laboratories. Address reprint requests to F. Mimouni, MD, University of Cincinnati College of Medicine, Department of Pediatrics, 231 Bethesda Avenue, Cincinnati, Ohio 45267-0C41.
PY - 1988/4/1
Y1 - 1988/4/1
N2 - We tested the hypothesis that repeated whole body suberythemal ultraviolet B (UVB) exposure would result in less increase of serum 25-hydroxyvitamin D (250HD) concentrations in black compared with white young adults with no significant change or racial differences in serum calciotropic hormones concentrations. Thirteen white and 7 black adults ranging from 22 to 35 years of age were submitted to sequential total body suberythemal doses of UVB (280—315 nm) biweekly for 6 weeks. Initial UVB dose was 5% below the minimal erythemal dose for the most sensitive skin, followed by 10% increase per exposure for 4 weeks. Blood samples were drawn weekly. Baseline 250HD concentrations were significantly lower in blacks compared to whites, but the increases in serum 250HD concentrations were similar in both groups; there were no significant differences by sex or age. Serum 24,25-dihydroxyvitamin D [24,25-(OH)2D] concentrations paralleled the serum 250HD response. Mean serum calcium (total and ionized), magnesium, phosphate, alkaline phosphatase, vitamin D binding protein, C-terminal parathyroid hormone, calcitonin, 1,25-dihydroxy vitamin D [l,25-(OH)2D], and osteocalcin concentrations did not differ between blacks and whites at any time. The ratio of the concentration of l,25-(OH)2D to 250HD in their serum was initially higher in blacks compared to whites (p<0.0001); the ratios decreased to levels similar to whites by the third UVB exposure. We conclude that, in blacks and whites, sequential suberythemal UVB exposure produces similar elevations of serum 250HD concentrations and unchanged calciotropic hormones concentrations. From the lack of racial difference in serum 250HD response, we suggest that sequential suberythemal ultraviolet exposure in this study resulted in maximal cutaneous previtamin D3 production, and that blacks and whites are equally capable of producing vitamin D3 at these doses.
AB - We tested the hypothesis that repeated whole body suberythemal ultraviolet B (UVB) exposure would result in less increase of serum 25-hydroxyvitamin D (250HD) concentrations in black compared with white young adults with no significant change or racial differences in serum calciotropic hormones concentrations. Thirteen white and 7 black adults ranging from 22 to 35 years of age were submitted to sequential total body suberythemal doses of UVB (280—315 nm) biweekly for 6 weeks. Initial UVB dose was 5% below the minimal erythemal dose for the most sensitive skin, followed by 10% increase per exposure for 4 weeks. Blood samples were drawn weekly. Baseline 250HD concentrations were significantly lower in blacks compared to whites, but the increases in serum 250HD concentrations were similar in both groups; there were no significant differences by sex or age. Serum 24,25-dihydroxyvitamin D [24,25-(OH)2D] concentrations paralleled the serum 250HD response. Mean serum calcium (total and ionized), magnesium, phosphate, alkaline phosphatase, vitamin D binding protein, C-terminal parathyroid hormone, calcitonin, 1,25-dihydroxy vitamin D [l,25-(OH)2D], and osteocalcin concentrations did not differ between blacks and whites at any time. The ratio of the concentration of l,25-(OH)2D to 250HD in their serum was initially higher in blacks compared to whites (p<0.0001); the ratios decreased to levels similar to whites by the third UVB exposure. We conclude that, in blacks and whites, sequential suberythemal UVB exposure produces similar elevations of serum 250HD concentrations and unchanged calciotropic hormones concentrations. From the lack of racial difference in serum 250HD response, we suggest that sequential suberythemal ultraviolet exposure in this study resulted in maximal cutaneous previtamin D3 production, and that blacks and whites are equally capable of producing vitamin D3 at these doses.
UR - http://www.scopus.com/inward/record.url?scp=0023772544&partnerID=8YFLogxK
U2 - 10.1080/07315724.1988.10720227
DO - 10.1080/07315724.1988.10720227
M3 - Article
C2 - 3361035
AN - SCOPUS:0023772544
SN - 0731-5724
VL - 7
SP - 111
EP - 118
JO - Journal of the American College of Nutrition
JF - Journal of the American College of Nutrition
IS - 2
ER -