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Getting Enough of the Sunshine Vitamin

Winter-time Reminder – Getting Enough of the Sunshine Vitamin

My husband’s birthday was a couple weeks ago – December 21st – and every year he reminds me he was born on the “darkest day of the year.” And, it’s true – in most years December 21st is the winter solstice, the day when the northern parts of the earth are tilted away from the sun by the maximum distance. For me, this is the perfect time of year to remind my clients, friends and my one-year-older husband about the importance of vitamin D.

Vitamin D is mysterious in some ways. For one thing, the fact that we can manufacture vitamin D by exposing our skin to direct sunlight actually disqualifies it as meeting the definition of a vitamin (I can’t explain why it’s still considered to be a vitamin). And, while we know vitamin D is essential to bone health (working to help calcium absorption), some evidence hints at key roles in reducing cancer risk, managing immunity, improving heart health and increasing insulin production.

There’s no mystery about getting adequate vitamin D, however – it’s not easy. First, there’s the issue of the inadvisability of sun exposure due to the risk for skin cancers. Second, even if sun exposure were recommended, the intensity away from the equator is not ideal for vitamin D production, especially for populations with dark skin. Third, excess body fat tends to capture the chemical precursors of vitamin D in overweight people, meaning the active compounds are not available. And fourth, not many foods are naturally rich in vitamin D (fatty fish like salmon and certain mushrooms), and the many foods fortified with vitamin D, like milk, fruit juices and cereals, are carbohydrates. For this reason, vitamin D is one of the few supplements I recommend.

Because vitamin D is so important I encourage you to ask your doctor to include a lab test for vitamin D – technically a test for 25 hydroxyvitamin D – at your next visit. There isn’t complete agreement in the medical community about what level is “ideal”, but there’s wide agreement that levels lower than 15 nanograms per milliliter (ng/mL) deserve attention. There’s not much we can do about late December being the darkest time of year, but we don’t have to be in the dark about whether we are maintaining adequate blood levels of this important compound.

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