Professor Caryl Nowson, Chair of Nutrition and Ageing at Deakin University, and coauthors wrote that vitamin D status had increasingly become a “significant public health issue in Australia and New Zealand” since the previous position statement released in 2005.
Improving vitamin D status has been shown to reduce all-cause mortality, and vitamin D plus calcium supplementation reduces the risk of falls and fractures in older people, while vitamin D insufficiency is associated with many diseases such as insulin resistance and some cancers, they wrote.
According to the authors, inadequate vitamin D status occurred in more than 50% of women during winter and spring, and in people residing in southern states.
They said for that people with moderately fair skin, adequate vitamin D levels are likely to be maintained in summer by a walk outside with arms (or equivalent area) exposed for 6-7 minutes mid morning or mid afternoon on most days.
“Short UV radiation exposures (of a few minutes) may be more efficient at producing vitamin D and cause less skin damage”, they wrote.
“In winter, the task is more difficult, and in many parts of the country, there is only sufficient UVB radiation to produce vitamin D around noon.”
The authors cautioned that vitamin D supplementation may be more appropriate than sun exposure for people at high risk of skin cancer.
Most adults are unlikely to obtain more than 5%-10% of their vitamin D requirement from dietary sources, according to the authors.
They said that, assuming minimal sun exposure, the recommended daily dose of vitamin D from dietary sources and supplementation sufficient to maintain adequate vitamin D levels had increased to 600 IU for most people.
Source :The Medical Journal of Australia