The Essential Vitamin D
In summer we all struggle to keep cool. But the up side of extra sunshine is that we don't have to worry about getting enough vitamin D. And did you know that vitamin D is necessary for maintaining good health and can even help you lose weight? Vitamin D forms in the skin when it is exposed to UV from sunlight. Vitamin D can also be obtained in some foods, such as margarine and some dairy products fortified with vitamin D, as well as oily fish, eggs and liver. Vitamin D is key to good bone and teeth health, preventing rickets in children and guarding against osteoporosis and fractures in adulthood by aiding calcium and phosphorus absorption.
It is very difficult to get enough vitamin D from food sources alone, as very few foods naturally contain vitamin D -- and those that do will not contain enough to optimize your levels.
Interestingly, the only vitamin not found in breast milk is vitamin D indicating we were designed to produce it by exposing our skin to natural sunlight rather than via food sources.
The best way to get enough vitamin D is from regular sun exposure. Occasional sunlight exposure to your face and hands is not sufficient for vitamin D nutrition for most people. During the Australian summer, a few minutes a day is enough for most people, however, in winter, the Australian Cancer Council indicates that two-three hours per week in required.
Contrary to popular belief, the best time to be in the sun for vitamin D production is actually as close to noon as possible. Ultraviolet light from the sun comes in two main wavelengths -- UVA and UVB. It's important for you to understand the difference between them, and your risk factors from each.
UVB wavelengths help your skin produce vitamin D, while UVA penetrate your skin more deeply and cause more free radical damage. UVA rays are quite constant during hours of daylight, unlike UVB, which are low in morning and evening and high at midday.
So to use the sun to maximize your vitamin D production and minimize your risk of skin damage, the middle of the day (roughly between 10:00 a.m. and 3:00 p.m.) is the best and safest time. It is important to note that sensible sun protection will not reduce your uptake of vitamin D and that supplements should only be taken under your GP’s supervision.