Vitamin D is important for brain health in many ways. It minimizes inflammatory pathways in the brain, regulates oxidative damage through enhancing glutathione production, and inhibits the uptake of reactive oxygen species into nerve cells. Vitamin D also minimizes excitotoxicity, the brain state where too much glutamate triggers an over-abundance of nerve activity.
Vitamin D is the vitamin our bodies make when sunlight hits the skin, which leaves many wondering why we keep hearing about Vitamin D deficiencies. UBV rays are the specific wavelength of sunlight that is needed to convert vitamin D in the skin. These rays are predominant when the sun is highest in the sky – often the same time people avoid being outdoors. Sunscreen, clothing, sunglasses, and glass windows with UV protection also do a terrific job of blocking the skin and the eyes from converting the sun’s rays into vitamin D. Based on these factors alone, many people may not be getting enough sunlight in the summer months to make enough vitamin D naturally. For people living in Northern climates, the sun’s path is too low in the sky between September and May, to make much of any vitamin D at all. For these reasons, many people’s levels of vitamin D decrease in winter months.
Vitamin D can be tested through a simple, inexpensive blood test. Laboratory ranges often consider 30 – 80 ng/ml to be normal. For people with depression, seasonal affective disorder, concussions, or neurodegenerative diseases, functional levels in the 50-80 ng/ml are better to aim for. A good daily dosage of vitamin D, if levels are in the normal range, is 2,000 – 4,000 IU/day in the summer, and 5,000 IU/day in the winter. People with low vitamin D levels need to supplement with at least 10,000 IU/day for 2-3 months, in order to bring deficient levels back into the normal range. It is always a good idea to retest vitamin D three months after starting a higher dose regimen, and back down on the dosage once levels are adequate.
Vitamin D get synthesized directly in the brain. Specific areas of the brain have large amounts of Vitamin D receptors, such as regions of the hippocampus (involved in memory and information recall). Vitamin D inhibits the production of inflammatory compounds in the body, such as pro-inflammatory cytokines and NFkB. This becomes quite important for people recovering from traumatic brain injuries. Chronic inflammatory processes in the brain following trauma, are the driving force behind many of the post-concussion symptoms people experience. In order to heal the brain, reducing inflammation is essential. Through inhibiting the pro-inflammatory cytokine and NFkB pathways, vitamin D, does exactly that.
In vivo research on nerve cells shows Vitamin D decreases the excitotoxicity of glutamate and blocks the uptake of reactive oxygen species into nerve cells. These are two of the distinct pathological processes that occur following traumatic brain injury, suggesting that Vitamin D can play an important role in protecting the brain after trauma. Researches also believe Vitamin D may be neuroprotective against seizures, Parkinson’s disease, and multiple sclerosis. It has been shown to have a beneficial effect on dopamine and serotonin pathways in the brain as well.
Vitamin D also plays an important role in mood, energy levels, and the immune system. People with seasonal affective disorder often report benefits from the use of indoor sun lights and Vitamin D supplementation. Vacations to warm and sunny paradise also do the trick.