Recommended Summer Sunlight Exposure Levels Can Produce Sufficient ( X 20 ng ml (cid:2) 1 ) but Not the Proposed Optimal ( X 32 ng ml (cid:2) 1 ) 25(OH)D Levels at UK Latitudes

Recommendations on limitation of summer sunlight exposure to prevent skin cancer may conflict with requirements to protect bone health through adequate vitamin D levels, the principal source being UVB in summer sunlight. We determined whether sufficient ( X 20 ng ml (cid:2) 1 ) and proposed optimal ( X 32 ng ml (cid:2) 1 ) 25(OH)D levels are attained by following UK guidance advising casual short exposures to UVB in summer sunlight, and performed the study under known conditions to enhance the specificity of future recommendations. During wintertime, when ambient UVB is negligible, 120 white Caucasians, aged 20–60 years, from Greater Manchester, UK (53.5 1 N) received a simulated summer’s sunlight exposures, specifically 1.3 standard erythemal dose, three times weekly for 6 weeks, while wearing T-shirt and shorts. The baseline winter data predict that 5% (confidence interval (CI): 2.7–8.6) of Greater Manchester white Caucasians have deficient ( o 5 ng ml (cid:2) 1 ) 25(OH)D, 62.5% (CI: 55.2–69.4) have insufficient, and only 2.9% (CI: 1.4–5.6) have proposed optimal levels. After the simulated summer exposures, 90 (CI: 84.9–93.7) and 26.2% (CI: 20.1–33.2) reached 20 and 32 ng ml (cid:2) 1 25(OH)D, respectively. Assuming midday UVB levels, sufficient but suboptimal vitamin D status is attained after a summer’s short (13 minutes) sunlight exposures to 35% skin surface area; these findings will assist future public health guidance on vitamin D acquisition.

[1]  J. Moan,et al.  Sunbeds as Vitamin D Sources , 2009, Photochemistry and photobiology.

[2]  C. la Vecchia,et al.  Dietary vitamin D and cancers of the oral cavity and esophagus. , 2009, Annals of oncology : official journal of the European Society for Medical Oncology.

[3]  Emily White,et al.  A cohort study of vitamin D intake and melanoma risk. , 2009, The Journal of investigative dermatology.

[4]  M. Holick,et al.  Vitamin D status: measurement, interpretation, and clinical application. , 2009, Annals of epidemiology.

[5]  H. Wulf,et al.  Sunbed Radiation Provokes Cutaneous Vitamin D Synthesis in Humans—A Randomized Controlled Trial , 2008, Photochemistry and photobiology.

[6]  G. Mishra,et al.  Predictors of 25-hydroxyvitamin D status among adults in two British national surveys. , 2008, The British journal of nutrition.

[7]  J. Moan,et al.  Sun beds and cod liver oil as vitamin D sources. , 2008, Journal of photochemistry and photobiology. B, Biology.

[8]  Lada Timotijevic,et al.  Current micronutrient recommendations in Europe: towards understanding their differences and similarities , 2008, European journal of nutrition.

[9]  A. Nohe,et al.  Molecular basis of the potential of vitamin D to prevent cancer , 2008, Current medical research and opinion.

[10]  M. Holick,et al.  Vitamin D and Skin Physiology: A D‐Lightful Story , 2007, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[11]  E. Hyppönen,et al.  Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. , 2007, The American journal of clinical nutrition.

[12]  P. Lips,et al.  13th Workshop consensus for vitamin D nutritional guidelines , 2007, The Journal of Steroid Biochemistry and Molecular Biology.

[13]  A. Webb,et al.  Calculated Ultraviolet Exposure Levels for a Healthy Vitamin D Status , 2006, Photochemistry and photobiology.

[14]  R. Vieth What is the optimal vitamin D status for health? , 2006, Progress in biophysics and molecular biology.

[15]  M. Holick Vitamin D: its role in cancer prevention and treatment. , 2006, Progress in biophysics and molecular biology.

[16]  G. Ziegelberger,et al.  International commission on non-ionizing radiation protection. , 2006, Progress in biophysics and molecular biology.

[17]  W. Willett,et al.  Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes. , 2006, The American journal of clinical nutrition.

[18]  O. Gillie A new government policy is needed for sunlight and vitamin D , 2006, The British journal of dermatology.

[19]  Barbara A Gilchrest,et al.  The vitamin D questions: how much do you need and how should you get it? , 2006, Journal of the American Academy of Dermatology.

[20]  B. Hollis Circulating 25-hydroxyvitamin D levels indicative of vitamin D sufficiency: implications for establishing a new effective dietary intake recommendation for vitamin D. , 2005, The Journal of nutrition.

[21]  A. Halpern,et al.  Diet and melanoma in a case-control study. , 2004, Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology.

[22]  H. Bischoff-Ferrari,et al.  Positive association between 25-hydroxy vitamin D levels and bone mineral density: a population-based study of younger and older adults. , 2004, The American journal of medicine.

[23]  M. Holick,et al.  Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. , 2004, The American journal of clinical nutrition.

[24]  C. J. Knill,et al.  McCance and Widdowson's the Composition of Foods sixth summary edition , 2003 .

[25]  A. Zittermann Vitamin D in preventive medicine: are we ignoring the evidence? , 2003, The British journal of nutrition.

[26]  Cecilia A. Hale,et al.  Calcium Absorption Varies within the Reference Range for Serum 25-Hydroxyvitamin D , 2003, Journal of the American College of Nutrition.

[27]  R. Lew,et al.  Effects of Vitamin D and Calcium Supplementation on Falls: A Randomized Controlled Trial , 2003, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[28]  R. Heaney,et al.  Effects of above average summer sun exposure on serum 25-hydroxyvitamin D and calcium absorption. , 2002, The Journal of clinical endocrinology and metabolism.

[29]  J. Berry,et al.  Vitamin D Metabolism, Rickets, and Osteomalacia , 2002, Seminars in musculoskeletal radiology.

[30]  B. Diffey,et al.  Guidelines for dosimetry and calibration in ultraviolet radiation therapy: a report of a British Photodermatology Group workshop , 2002, The British journal of dermatology.

[31]  F. Anderson Nutrition and bone health: with particular reference to calcium and vitamin D. Report of the Subgroup on Bone Health, Working Group on the Nutritional Status of the Population of the Committee on Medical Aspects of the Food Nutrition Policy. , 1999, Reports on health and social subjects.

[32]  C. Potten,et al.  Human melanocytes and keratinocytes exposed to UVB or UVA in vivo show comparable levels of thymine dimers. , 1998, The Journal of investigative dermatology.

[33]  M. Holick,et al.  Redefining vitamin D insufficiency , 1998, The Lancet.

[34]  J. Mark Elwood,et al.  Melanoma and sun exposure: An overview of published studies , 1997, International journal of cancer.

[35]  B L Diffey,et al.  The standard erythema dose: a new photobiological concept , 1997, Photodermatology, photoimmunology & photomedicine.

[36]  Douglas G. Altman,et al.  Practical statistics for medical research , 1990 .

[37]  J. Zerwekh,et al.  The effect of ultraviolet B radiation treatments on calcium excretion and vitamin D metabolites in kidney stone formers. , 1989, Clinical nephrology.

[38]  M. Holick,et al.  Sunlight regulates the cutaneous production of vitamin D3 by causing its photodegradation. , 1989, The Journal of clinical endocrinology and metabolism.

[39]  M. Holick,et al.  Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. , 1988, The Journal of clinical endocrinology and metabolism.

[40]  R. Anderson,et al.  Spectral character of sunlight modulates photosynthesis of previtamin D3 and its photoisomers in human skin. , 1982, Science.

[41]  Joint Fao Who Expert Consultation on Human Vitamin and M Requirements Vitamin and mineral requirements in human nutrition , 2005 .

[42]  E. Gunter,et al.  Hypovitaminosis D in medical inpatients. , 1998, The New England journal of medicine.

[43]  P. Galan,et al.  Prevalence of Vitamin D Insufficiency in an Adult Normal Population , 1997, Osteoporosis International.

[44]  T. Ohnaka [Health effects of ultraviolet radiation]. , 1993, The Annals of physiological anthropology = Seiri Jinruigaku Kenkyukai kaishi.

[45]  B. Holland,et al.  Milk Products and Eggs: Fourth Supplement to McCance and Widdowson's the Composition of Foods , 1989 .

[46]  Intakes for Calcium , Phosphorus , Magnesium , Vitamin D , and Fluoride , 1974 .

[47]  J. Higginson,et al.  International Agency for Research on Cancer. , 1968, WHO chronicle.