Details

Autor(en) / Beteiligte

• Binkley, N
• Novotny, R
• Krueger, D
• Kawahara, T
• Daida, Y. G
• Lensmeyer, G
• Hollis, B. W
• Drezner, M. K

Titel

Low Vitamin D Status despite Abundant Sun Exposure

Ist Teil von

• The journal of clinical endocrinology and metabolism, 2007-06, Vol.92 (6), p.2130-2135

Ort / Verlag

Bethesda, MD: Endocrine Society

Erscheinungsjahr

2007

Quelle

Oxford Journals 2020 Medicine

Beschreibungen/Notizen

• Context: Lack of sun exposure is widely accepted as the primary cause of epidemic low vitamin D status worldwide. However, some individuals with seemingly adequate UV exposure have been reported to have low serum 25-hydroxyvitamin D [25(OH)D] concentration, results that might have been confounded by imprecision of the assays used. Objective: The aim was to document the 25(OH)D status of healthy individuals with habitually high sun exposure. Setting: This study was conducted in a convenience sample of adults in Honolulu, Hawaii (latitude 21°). Participants: The study population consisted of 93 adults (30 women and 63 men) with a mean (sem) age and body mass index of 24.0 yr (0.7) and 23.6 kg/m2 (0.4), respectively. Their self-reported sun exposure was 28.9 (1.5) h/wk, yielding a calculated sun exposure index of 11.1 (0.7). Main Outcome Measures: Serum 25(OH)D concentration was measured using a precise HPLC assay. Low vitamin D status was defined as a circulating 25(OH)D concentration less than 30 ng/ml. Results: Mean serum 25(OH)D concentration was 31.6 ng/ml. Using a cutpoint of 30 ng/ml, 51% of this population had low vitamin D status. The highest 25(OH)D concentration was 62 ng/ml. Conclusions: These data suggest that variable responsiveness to UVB radiation is evident among individuals, causing some to have low vitamin D status despite abundant sun exposure. In addition, because the maximal 25(OH)D concentration produced by natural UV exposure appears to be approximately 60 ng/ml, it seems prudent to use this value as an upper limit when prescribing vitamin D supplementation.