Vitamin D has a significant effect many tissues and cells and controls an enormous number of genes, including some associated with cancers, autoimmune disease, and infection. However, it also has an incredible effect on our mood and cognition, especially in the winter months when we need it most.
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| Let the Sun Shine In |
For the past several years, there has been considerable interest in the role vitamin D plays in improving health and preventing disease. Significant negative associations are found between vitamin D levels and disease severity. Hardly a month goes by without news about the risks of vitamin D deficiency or about a potential role for the vitamin in warding off diseases, including breast cancer, multiple sclerosis, and even schizophrenia.
Researchers have discovered specific molecular signaling events by which vitamin D prevents inflammation. In their experiments, they showed that low levels of Vitamin D, comparable to levels found in millions of people, failed to inhibit the inflammatory cascade--a series of rapid biochemical events which propagates and matures the inflammatory response. However, levels considered adequate did inhibit inflammatory signaling. They reported these results in the The Journal of Immunology.
Depression and Mood
Previous data has shown in the International Archives of Medicine that people with vitamin D deficiency are at an 85 percent increased risk of having current depressive episodes, compared with people with sufficient levels. People with higher blood levels of vitamin D also live significantly longer than people who have low blood levels of the vitamin.
“Although the direction of the cause and effect relation between depression and vitamin D deficiency is not known clearly at this time, in public health perspective, the coexistence of vitamin D and depression in the US population at large is a concern,” the researchers stated.
“It is important to identify persons who are at risk for vitamin D deficiency and/or for depression and to intervene early because these two conditions have enormous negative consequences on long term health.”
We know that geographic differences in toxicant exposure could interact with other environmental factors in a disorder such as multiple sclerosis,where a reduction in sunlight and vitamin D levels at increased latitudes has been implicated.
Vitamin D is somewhat of an unusual "vitamin," because it can be made in the body from sunlight and most foods do not contain vitamin D unless added by fortification. Synthesis of vitamin D in the body requires exposure to ultraviolet light and can be influenced by genetics, skin color, and sun exposure.
the World Health Organization (WHO) forecasts that within 20 years more people will be affected by depression than any other health problem; it ranks depression as the leading cause of disability worldwide, with around 120 million people affected.
This is not the first time that vitamin D has been linked to symptoms of depression. Dutch scientists reported in 2008 in the Archives of General Psychiatry that low levels of the vitamin and higher blood levels of the parathyroid hormone (PTH) were associated with higher rates of depression among 1,282 community residents aged between 65 and 95.
Furthermore, a review by Bruce Ames and Joyce McCann from the Children's Hospital and Research Center Oakland highlighted the role of the vitamin in maintaining brain health, noting the wide distribution of vitamin D receptors throughout the brain.
According to the review (FASEB Journal, Vol.22, pp. 982-1001), the vitamin has been reported to affect proteins in the brain known to be directly involved in learning and memory, motor control, and possibly even maternal and social behaviour. Depression in the elderly is highly prevalent and can increase the risk of medical illnesses, worsen the outcome of other medical illnesses, and may increase mortality.
How Much Vitamin D Do You Need for Your Best Health?
According to the review (FASEB Journal, Vol.22, pp. 982-1001), the vitamin has been reported to affect proteins in the brain known to be directly involved in learning and memory, motor control, and possibly even maternal and social behaviour. Depression in the elderly is highly prevalent and can increase the risk of medical illnesses, worsen the outcome of other medical illnesses, and may increase mortality.
How Much Vitamin D Do You Need for Your Best Health?
The optimal range is somewhere between 50 and 60 ng/ml (125 to 150 nmol/l). To convert ng/ml to nmol/l, simply multiply by 2.5.
Unfortunately, the only way to know where you're at is to ask your doctor to include 25 (OH) D, also known as 25-hydroxy D, with your blood work during your next checkup. Some labs test for 1,25 hydroxy D, which isn't as accurate a marker of your vitamin D status as 25 hydroxy D, so be sure to specifically ask for 25 hydroxy D.
You want your 25 hydroxy D level to be at least 30 ng/ml (75 nmol/l), but again, based on the research that I have reviewed, mainly that of Dr. Michael Holick, the optimal range appears to be 50 to 60 ng/ml. Some prominent physicians and vitamin D experts feel that one can go even higher, even up to 80 ng/ml. But my suggestion is to err on the side of caution and aim to be in the 50 to 60 range.
The 50 to 60 range is based on numerous studies that show strong relationships between these levels and reduced risk of a wide variety of chronic diseases and increased lifespan. This range is also based on the 25 hydroxy D levels of healthy people living in areas of the world (tropical and subtropical regions) where it's quite common to receive more than enough sunlight exposure to ensure regular vitamin D production.
But here's an important point that you want to keep in mind: When sunlight creates vitamin D in a healthy person and that person's 25 hydroxy D is in the optimal range, that person is almost certainly benefiting from other natural compounds that are generated with sunlight exposure. Dr. Holick calls these other compounds "photo products," and he and his team are currently researching the makeup and benefits of these photo products.
Put another way, establishing optimal vitamin D status mainly via healthy sunlight exposure may provide more health benefits than establishing optimal vitamin D status mainly via foods and supplements. Correct usage of foods and supplements only gives you the right amount of vitamin D - they don't generate the photo products that sunlight does.
At the same time, it's worth remembering that even responsible exposure to sunlight comes with some undesirable effects, like premature aging of skin and possibly increased risk of non-melanoma skin cancers, depending on your history of sunlight exposure.
So it's too early to say which is more desirable between getting vitamin D mainly from sunlight vs. mainly from foods and supplements.
What we do know for sure is that keeping your 25 hydroxy D level somewhere between 50 and 60 ng/ml, possibly even up to 65 ng/ml can significantly decrease your risk of all types of disease and increase your lifespan. And a wise approach is likely getting vitamin D from a combination of responsible sunlight exposure and foods and supplements that come with vitamin D.
Vitamin D is best obtained by sunlight, but if pursuing supplementation, look for high quality vitamin D3 cholecalciferol and stay away from those with dangerous preservatives such as potassium sorbate.
Mae Chan holds degrees in both physiology and nutritional sciences. She is also blogger and and technology enthusiast with a passion for disseminating information about health.
This article first appeared in Prevent Disease