BACKGROUND: Vitamin D is essential for bone health, and cutaneous synthesis is an important source. South Asians cannot attain adequate amounts of vitamin D by following general recommendations on summer sunlight exposure at northerly latitudes, and increased exposure may be appropriate for improving their vitamin D status. OBJECTIVE: We examined the efficacy of a dose range of simulated summer sunlight exposures in raising vitamin D status in UK adults of South Asian ethnicity. DESIGN: In a dose-response study, healthy adults of South Asian ethnicity (n = 60; 20-60 y old) received 1 of 6 ultraviolet exposures ranging from 0.65 to 3.9 standard erythema doses (SEDs), which were equivalent to 15-90 min unshaded noontime summer sunlight at 53.5°N (Manchester, United Kingdom), 3 times/wk for 6 wk, while wearing casual clothes that revealed a 35% skin area. Serum 25-hydroxyvitamin D [25(OH)D] was measured weekly, and dietary vitamin D was estimated. RESULTS: At baseline, all completing participants (n = 51) were vitamin D insufficient [25(OH)D concentrations <20 ng/mL], and a high proportion of participants were deficient [35% of subjects had 25(OH)D concentrations <5 ng/mL, and 90% of subjects had 25(OH)D concentrations <10 ng/mL, which are concentrations at which osteomalacia and rickets occur). The 25(OH)D concentration rose significantly in all dose groups. Postcourse, all participants achieved 25(OH)D concentrations ≥5 ng/mL, whereas only 6 subjects attained 25(OH)D concentrations ≥20 ng/mL. Participants who received exposures ≥1.95 SEDs (equivalent to 45 min unshaded sunlight; n = 33) attained a mean (±SD) 25(OH)D concentration of 15.7 ± 5 ng/mL (mean rise: 8.7 ± 5.7 ng/mL; 95% CI: 6.8, 10.6 ng/mL; P < 0.001), and 94% of subjects achieved concentrations >10 ng/mL. CONCLUSIONS: Targeted guidance on sunlight exposure could usefully enhance vitamin D status to avoid deficiency [25(OH)D concentration >10 ng/mL] in South Asians living at latitudes distant from the equator. This trial was registered at the ISRCTN Register (www.isrctn.org) as 07565297.
BACKGROUND:Vitamin D is essential for bone health, and cutaneous synthesis is an important source. South Asians cannot attain adequate amounts of vitamin D by following general recommendations on summer sunlight exposure at northerly latitudes, and increased exposure may be appropriate for improving their vitamin D status. OBJECTIVE: We examined the efficacy of a dose range of simulated summer sunlight exposures in raising vitamin D status in UK adults of South Asian ethnicity. DESIGN: In a dose-response study, healthy adults of South Asian ethnicity (n = 60; 20-60 y old) received 1 of 6 ultraviolet exposures ranging from 0.65 to 3.9 standard erythema doses (SEDs), which were equivalent to 15-90 min unshaded noontime summer sunlight at 53.5°N (Manchester, United Kingdom), 3 times/wk for 6 wk, while wearing casual clothes that revealed a 35% skin area. Serum 25-hydroxyvitamin D [25(OH)D] was measured weekly, and dietary vitamin D was estimated. RESULTS: At baseline, all completing participants (n = 51) were vitamin D insufficient [25(OH)D concentrations <20 ng/mL], and a high proportion of participants were deficient [35% of subjects had 25(OH)D concentrations <5 ng/mL, and 90% of subjects had 25(OH)D concentrations <10 ng/mL, which are concentrations at which osteomalacia and rickets occur). The 25(OH)D concentration rose significantly in all dose groups. Postcourse, all participants achieved 25(OH)D concentrations ≥5 ng/mL, whereas only 6 subjects attained 25(OH)D concentrations ≥20 ng/mL. Participants who received exposures ≥1.95 SEDs (equivalent to 45 min unshaded sunlight; n = 33) attained a mean (±SD) 25(OH)D concentration of 15.7 ± 5 ng/mL (mean rise: 8.7 ± 5.7 ng/mL; 95% CI: 6.8, 10.6 ng/mL; P < 0.001), and 94% of subjects achieved concentrations >10 ng/mL. CONCLUSIONS: Targeted guidance on sunlight exposure could usefully enhance vitamin D status to avoid deficiency [25(OH)D concentration >10 ng/mL] in South Asians living at latitudes distant from the equator. This trial was registered at the ISRCTN Register (www.isrctn.org) as 07565297.
Authors: G H Bernhard; R E Neale; P W Barnes; P J Neale; R G Zepp; S R Wilson; A L Andrady; A F Bais; R L McKenzie; P J Aucamp; P J Young; J B Liley; R M Lucas; S Yazar; L E Rhodes; S N Byrne; L M Hollestein; C M Olsen; A R Young; T M Robson; J F Bornman; M A K Jansen; S A Robinson; C L Ballaré; C E Williamson; K C Rose; A T Banaszak; D -P Häder; S Hylander; S -Å Wängberg; A T Austin; W -C Hou; N D Paul; S Madronich; B Sulzberger; K R Solomon; H Li; T Schikowski; J Longstreth; K K Pandey; A M Heikkilä; C C White Journal: Photochem Photobiol Sci Date: 2020-05-20 Impact factor: 3.982
Authors: Craig F Munns; Nick Shaw; Mairead Kiely; Bonny L Specker; Tom D Thacher; Keiichi Ozono; Toshimi Michigami; Dov Tiosano; M Zulf Mughal; Outi Mäkitie; Lorna Ramos-Abad; Leanne Ward; Linda A DiMeglio; Navoda Atapattu; Hamilton Cassinelli; Christian Braegger; John M Pettifor; Anju Seth; Hafsatu Wasagu Idris; Vijayalakshmi Bhatia; Junfen Fu; Gail Goldberg; Lars Sävendahl; Rajesh Khadgawat; Pawel Pludowski; Jane Maddock; Elina Hyppönen; Abiola Oduwole; Emma Frew; Magda Aguiar; Ted Tulchinsky; Gary Butler; Wolfgang Högler Journal: J Clin Endocrinol Metab Date: 2016-01-08 Impact factor: 5.958