We live in Winnipeg, or Winterpeg as it's affectionately known. Vitamin D is made in the skin upon exposure to the sun's UV rays.
A lack of direct sunlight in winter means we do not easily make vitamin D from October to April. Need I say more? According to a few conflicting media reports as of late, yes, it would turn out I do...
Vitamin D is more than a vitamin. It's actually a hormone. You see, a vitamin, by definition, must be consumed through the diet, whereas hormones are synthesized by the body. In fact, vitamin D is manufactured from cholesterol in humans as well.
Studies on its effects are plentiful, with its benefits ranging from reduced inflammation to protecting the brain from free radicals. We know it is one of the more critical nutrients linked to depression, and restoring levels can support mood. A study published in the Psychopharmacology Journal 1998 showed years back how vitamin D can even enhance mood in healthy subjects during winter.
The adrenal glands (where the body's major stress hormone, cortisol, is produced) use vitamin D to regulate brain chemistry by producing dopamine and epinephrine, thereby impacting our mood, energy and ability to cope.
Acting on receptors throughout the body, vitamin D is important for much more than bone health. It's true it aids in the absorption of calcium in the digestive tract and helps the body utilize phosphorus. It's also necessary for thyroid function and helps the pancreas to release insulin.
The literature is clear vitamin D levels are often lower in people with neurodegenerative diseases such as Parkinson's, Alzheimer's and multiple sclerosis. Higher blood levels are associated with a lower relapse risk of MS. According to a seven-year followup study published in the Journals of Gerontology, high vitamin D intake is also associated with a lower risk of Alzheimer's.
How do we test for this important nutrient? I believe testing vitamin D levels is crucial in order to optimize the body's function. Only about a third of Canadians have vitamin D level above 75 nmol/L, the minimum considered optimal for health according to Health Canada.
"You don't need to test. Every one just needs 2,000 IU daily in winter," is a comment people are often told by their physician. After all, testing costs are not insignificant. But how is this personalized? I often meet patients who have been supplementing with more than 2,000 IU for years, and their level is still low. The difference is that this "one size fits all" advice is focused on preventing disease, not supporting optimal function. To overcome this disconnect, I order routine vitamin D tests for my patients through a private lab.
We don't want too little, and we also don't want too much. Since vitamin D is fat-soluble, it will be absorbed by your body best when taken with fat. It will also store in fat.
So when it comes to supplementation, there are certain forms that are a much better return on your investment. The best is a highly concentrated vitamin D liquid. Since the formulation is oil-based, the active ingredient is readily available to your body. One tiny little drop may provide 1,000 IUs.
Second choice would be a gel cap, which has an oily centre. Our last-place contestant -- the one most people have on hand -- is the tablet.
Food can be a source of vitamin D, from red meat and fish to mushrooms and sunflower seeds. Butter, eggs and of course fortified milk are providers as well.
Exposing the face and arms (without sunscreen) to direct sunlight for 10 to 15 minutes three times weekly can help us support vitamin D levels. I suppose that's if the wind chill doesn't kill you first.
So if the groundhog sees his shadow, he may be giving us a better clue than the classic six more weeks of winter. We know that when the sun is shining, it's a perfect day to 'd-light' in our own production of vitamin D.
Tara Maltman-Just is the executive clinician and licensed pharmacist at Vitality Integrative Medicine in Winnipeg. www.vitalityintegrativemedicine.com.