UK Food Standards Agency Workshop Report: an investigation of the relative contributions of diet and sunlight to vitamin D status
- 4 June 2010
- journal article
- review article
- Published by Cambridge University Press (CUP) in British Journal of Nutrition
- Vol. 104 (4), 603-611
- https://doi.org/10.1017/s0007114510002138
Abstract
The UK Food Standards Agency (FSA) convened an international group of scientific experts to review three Agency-funded projects commissioned to provide evidence for the relative contributions of two sources, dietary vitamin D intake and skin exposure to UVB rays from sunlight, to vitamin D status. This review and other emerging evidence are intended to inform any future risk assessment undertaken by the Scientific Advisory Committee on Nutrition. Evidence was presented from randomised controlled trials to quantify the amount of vitamin D required to maintain a serum 25-hydroxy vitamin D (25OHD) concentration >25 nmol/l, a threshold that is regarded internationally as defining the risk of rickets and osteomalacia. Longitudinal evidence was also provided on summer sunlight exposure required to maintain 25OHD levels above this threshold in people living in the British Isles (latitude 51°–57°N). Data obtained from multi-level modelling of these longitudinal datasets showed that UVB exposure (i.e. season) was the major contributor to changes in 25OHD levels; this was a consistent finding in two Caucasian groups in the north and south of the UK, but was less apparent in the one group of British women of South Asian origin living in the south of the UK. The FSA-funded research suggested that the typical daily intake of vitamin D from food contributed less than UVB exposure to average year-round 25OHD levels in both Caucasian and Asian women. The low vitamin D status of Asian women has been acknowledged for some time, but the limited seasonal variation in Asian women is a novel finding. The Workshop also considered the dilemma of balancing the risks of vitamin D deficiency (from lack of skin exposure to sunlight in summer) and skin cancer (from excessive exposure to sunlight with concomitant sunburn and erythema). Cancer Research UK advises that individuals should stay below their personal sunburn threshold to minimise their skin cancer risk. The evidence suggests that vitamin D can be produced in summer at the latitude of the UK, with minimal risk of erythema and cell damage, by exposing the skin to sunlight for a short period at midday, when the intensity of UVB is at its daily peak. The implications of the new data were discussed in the context of dietary reference values for vitamin D for the general population aged 4–64 years. Future research suggestions included further analysis of the three FSA-funded studies as well as new research.Keywords
This publication has 25 references indexed in Scilit:
- Reply to R ViethThe American Journal of Clinical Nutrition, 2009
- Experimentally observed vitamin D requirements are higher than extrapolated onesThe American Journal of Clinical Nutrition, 2009
- A pooled analysis of melanocytic nevus phenotype and the risk of cutaneous melanoma at different latitudesInternational Journal of Cancer, 2008
- Assessment of ecological regression in the study of colon, breast, ovary, non-Hodgkin's lymphoma, or prostate cancer and residential UVEuropean Journal of Cancer Prevention, 2008
- Nutrition and bone health projects funded by the UK Food Standards Agency: have they helped to inform public health policy?British Journal of Nutrition, 2007
- What do we currently know about nutrition and bone health in relation to United Kingdom public health policy with particular reference to calcium and vitamin D?British Journal of Nutrition, 2007
- Calculated Ultraviolet Exposure Levels for a Healthy Vitamin D StatusPhotochemistry and Photobiology, 2006
- Who, what, where and when—influences on cutaneous vitamin D synthesisProgress in Biophysics and Molecular Biology, 2006
- Calculated Ultraviolet Exposure Levels for a Healthy Vitamin D StatusPhotochemistry and Photobiology, 2006
- Meta-analysis of risk factors for cutaneous melanoma: III. Family history, actinic damage and phenotypic factorsEuropean Journal of Cancer, 2005