The role of sunlight exposure in determining the vitamin D status of the U.K. white adult population.
Br J Dermatol
; 163(5): 1050-5, 2010 Nov.
Article
in En
| MEDLINE
| ID: mdl-20716215
ABSTRACT
BACKGROUND:
Vitamin D is necessary for bone health and is potentially protective against a range of malignancies. Opinions are divided on whether the proposed optimal circulating 25-hydroxyvitamin D [25(OH)D] level (≥ 32 ng mL⻹) is an appropriate and feasible target at population level.OBJECTIVES:
We examined whether personal sunlight exposure levels can provide vitamin D sufficient (≥ 20 ng mL⻹) and optimal status in the U.K. public.METHODS:
This prospective cohort study measured circulating 25(OH)D monthly for 12 months in 125 white adults aged 20-60 years in Greater Manchester. Dietary vitamin D and personal ultraviolet radiation (UVR) exposure were assessed over 1-2 weeks in each season. The primary analysis determined the post-summer peak 25(OH)D required to maintain sufficiency in wintertime.RESULTS:
Dietary vitamin D remained low in all seasons (median 3·27 µg daily, range 2·76-4·15) while personal UVR exposure levels were high in spring and summer, low in autumn and negligible in winter. Mean 25(OH)D levels were highest in September [28·4 ng mL⻹; 28% optimal, zero deficient (<5 ng mL⻹)], and lowest in February (18·3 ng mL⻹; 7% optimal, 5% deficient). A February 25(OH)D level of 20 ng mL⻹ was achieved following a mean (95% confidence interval) late summer level of 30·4 (25·6-35·2) and 34·9 (27·9-41·9) ng mL⻹ in women and men, respectively, with 62% of variance explained by gender and September levels.CONCLUSIONS:
Late summer 25(OH)D levels approximating the optimal range are required to retain sufficiency throughout the U.K. winter. Currently the majority of the population fails to reach this post-summer level and becomes vitamin D insufficient during the winter.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sunlight
/
Vitamin D
/
Vitamins
Type of study:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Risk_factors_studies
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Country/Region as subject:
Europa
Language:
En
Journal:
Br J Dermatol
Year:
2010
Document type:
Article
Affiliation country:
United kingdom