By Perry Holman, Executive Director, Vitamin D Society

This year’s long winter throughout much of Canada will have depleted many Canadians’ vitamin D levels to dangerously low levels.

Statistics Canada reports, 38% of Canadians are now below the recommended vitamin D level from Health Canada of 50 nmol/L, 75% of Canadians are below the level recommended by Osteoporosis Canada to prevent bone disease of 75 nmol/L, and 93% of Canadians are below the optimal vitamin D levels recommended by 48 vitamin D scientists of 100 nmol/L for best overall health.

Sun exposure, specifically UVB exposure, is the primary source of vitamin D and is needed to restore our vitamin D levels. When you expose bare skin to summer sunlight at midday, a cholesterol in your skin is converted into previtamin D and enters your bloodstream.

Part of the problem leading to vitamin D deficiency is the advice from health organizations to reduce sun exposure especially at midday in the summer when UVB is the strongest to help prevent skin cancer. Some want you to wear sunscreen all day, everyday which prevents sunburns and reduces vitamin D production to almost nil. Some make these sun prevention recommendations without considering the consequences it will have on your vitamin D levels. Health organizations should take your overall health into consideration.

For example, research has shown that women who get more sun exposure live longer than women who do not. And that older women who get more sun exposure have a 50% reduced risk of breast cancer.

What we need to have is balance and a little common sense. Know your skin and skin type and protect yourself from overexposure, but try to get enough regular sun exposure to boost your vitamin D levels without sunburning as recommended by some UK agencies. How can you do this?

- The best time to make vitamin D from sun exposure is midday from April to October, between 10am-2pm, when the UV index is above 3 and your shadow is shorter than your height.

- Know your skin and skin type and ensure that you do not burn. Skin type 1 people, who always burn and never tan, can only tolerate brief, incidental sun exposure without sunburning and therefore are at risk of vitamin D deficiency.

- For people who can receive some sun exposure without burning, start with small exposures and gradually increase as your skin gets acclimatized to the sun.

- The more skin that is exposed to the sun, the more vitamin D you will make and the quicker you will make it.

- Get some unprotected sun exposure first and if you are going to be out longer take protective measures such as clothing/hat or shade to make sure you do not burn or put on sunscreen.

I hope you have a sunny summer without sunburn while replenishing your depleted vitamin D levels before autumn!