* The following guest post was contributed by Charlotte Walker.
For the past few decades the importance of staying safe in the sun has been repeatedly stressed. Too much exposure to the sun’s harmful ultraviolet rays can cause sunburn and in some cases, lead to skin cancer. However, getting enough sun exposure is vital for one particular bodily process: the synthesis of Vitamin D (1).
Vitamin D is required for a number of important functions in the body, and the extent of its effects are still being fully researched. A key role that the vitamin plays is in the regulation of calcium and phosphate, which in turns affects the health of your teeth and bones. A Vitamin D deficiency can therefore lead to bone conditions such as rickets (2).
Vitamin D is present in very few foods and so the vast majority – around 90 percent – of our intake of the vitamin comes from direct sunlight (3). The amount of sunlight that is needed for your body to synthesise Vitamin D depends of the colour of your skin, as melanin (the pigment that darkens skin) blocks the amount of UV light that is able to get through. This means that people with black or dark skin tones need more sunlight exposure to get enough of the vitamin (4).
Due to the way Vitamin D is produced, there are certain groups who are particularly at risk of a deficiency. According to the Food standards Agency these include people who:
• are of Asian origin
• always cover up all your skin when outside
• rarely get outdoors
• eat no meat or oily fish
The amount of time you spend in the sun also affects how much Vitamin D you are able to produce. Around 2 sessions of 5 to 30 minutes exposure to sunlight (without sunscreen) should be sufficient for most people .
Older people and pregnant women are advised to take 10 micrograms of the vitamin each day. Supplements like Vitamin D powder and capsules may be ideal.
About the Guest Author
Charlotte Walker writes professionally on a number of health topics relating to vitamin supplementation, particularly those featured in the news. Most recently this includes Vitamin D and its importance to the health of the body. You can follow her on Twitter using @charlottewalker.
(1) Bupa (2004). Vitamin D and sunlight may reduce cancer risk.
(2) Food standards Agency (2010). Vitamin D.
(3) Health Research Forum (2005). Sunlight, Vitamin D and Health (pdf)
(4) Patient UK (2008). Vitamin D Deficiency.
Image by Angel T