Before discussing an individual vitamin, I want to be very clear:
Our body needs a multitude of vitamins at the right (optimal) levels on a continuous basis. One vitamin is rarely the answer for our best health, but many are vital to continued health.
As a child I used to joke around about wanting to move to a different country just because of the weather changes in the winter months. We have long winters in Canada, and depending on where you are, less sun exposure as well.
When we lose sun exposure in the winter, we lose the ability to naturally produce vitamin D, as our body makes vitamin D through sun-exposure on the surface of the skin. The active form of Vitamin D is D3, which is sun-exposed. Vitamin D3 is critical not only for the functioning of our immune system (turns on very vital chemical reactions to cause our immune system to “fight” foreign invaders), but it is also involved in the production of chemicals in our brain (dopamine, norepinephrine, and epinephrine), chemicals when they are imbalanced are implicated in many mood disorders, including schizophrenia.
Many people suffer from seasonal affective disorder (SAD), which is thought to be associated with lack of sunlight during the winter months. The (direct) connection between vitamin D, sunlight loss, and feeling blue even to the point of depression is not entirely understood at this time. What we DO know is that as a fat-soluble vitamin, Vitamin D has the capacity to act like a hormone and interface with our hormone systems. Vitamin D receptors are also present in the hypothalamus, a brain centre that coordinates the immune system and the hormone system. The hypothalamus interfaces with an important brain centre called the pineal gland, which is involved in the processing of light and dark, and our brain’s understanding of what is day and what is night. Melatonin, a hormone produced in the pineal gland in the darkness, is in the same chemical pathway as our happy neurochemical, serotonin. As you can imagine, if more melatonin is produced in the darkness during the winter months, then less serotonin is produced. Vitamin D is an integral part of this process, but the direct connection is again, quite misunderstood.
We now know that Vitamin D deficiency is rampant and pervasive, especially in countries in the northern hemisphere (above the equator). Optimal levels in the bloodstream are now documented to be 78 pg/mL.
Recently in Ontario, OHIP has been restricting requests for vitamin D3 levels with the assumption everyone is Vitamin D deficient! This is slightly concerning. If we do not know what levels of vitamin D from which we start, how can we properly supplement? As Dr. Alan Gaby MD has outlined in a recent interview, we do not know the implications of large doses of vitamin D over time, and as vitamin D is vital in bone health and directing calcium into the bones, we must assume that if the bones do not have the proper levels of vitamins (vitamins A, D, E, K2, calcium, magnesium, boron, strontium) then increasing one of the vitamins in this delicate interplay we may be throwing off the balance in the body. Additionally, when we are truly deficient, the proper dosages must be prescribed to bring the body back to balance.
Please, before supporting yourself with vitamin D for your seasonal or pervasive depressive symptoms, do see your naturopathic doctor or your medical doctor to assess your vitamin D levels. If they are in the low range of normal, it may be prudent to moderately support your levels before going into the winter months. If they are already depleted, then the proper dosages must be given to get you out of the doldrums and back to feeling like your fabulous self.