VITAMIN D SUPPLEMENTATION & SUN

Q. How much time per day do I need to be outside to get enought Vitamin D and does it have to be a sunny day? Also what type of sun protection should I be using?

A. Great question! We have heard so much about vitamin D and the immense benefits it has on so many facets of health, including immune support and regulation, osteoporosis prevention, prevention of heart disease and management of Type II Diabetes. We also know that our bodies synthesize vitamin D through the skin on exposure to sun, but as always there are exceptions to this rule and a variety of factors that interfere this natural process. Here's how it works.

UV radiation penetrates uncovered skin and converts cutaneous 7 dehydrocholesterol to pre-vitamin D3. The pre-vitamin is then converted to the usable D3 form. Factors including season, time of day, cloud cover, smog, skin melanin content, and sunscreen all effect vitamin D synthesis through the skin. In Canada, for instance, based on our latitude, we can synthesize vitamin D from the sun during a maximum of only 6 months of the year (approximately April/May to Sept./Oct.).

Supplementation during the other 6 months of the year is necessary. Weather will affect our vitamin D status. Even during the warmer months, synthesis may be impaired if there is a lot of cloud cover or a smog. Full sun or scattered cloud cover is optimal.

It is also important here to reiterate that the conversion process will only take place if the skin is uncovered. If sunscreen is applied properly and is at a level of SPF 8 or more, the skin is considered covered and the UV rays necessary for vitamin D conversion are filtered out preventing this process from occurring.

How long do we need to be exposed?
5-30 minutes of direct sunlight between 10am and 3pm, only 2 days a week to the face, arms, legs or back is sufficient for adequate amounts of vitamin D to be synthesized. As the correlation between UV rays and skin cancer is well known and can be deadly, always be cautious while in the sun unprotected. For some individuals, a half hour of unprotected sun is enough to burn. You may choose to do only 5-10 minutes a day 3-4 times a week if you are more sensitive to the sun. Talk to you healthcare professional if you have concerns about unprotected sun exposure.

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