Here Comes the Sun - The Need For Vitamin D
Our knowledge base on Vitamin D has increased over the last few years. Vitamin D has generally been associated with Calcium absorption which promoted healthy bone growth. As such, it has been recognized as a preventive tool for osteoporosis. Vitamin D also reduces inflammation throughout the body. There has been a recent concentration of research on the affect of Vitamin D on the brain and in relation to dementia.
So how does a vitamin that you receive from sunlight work? It really isn’t so mysterious. Ultraviolet rays from the sun hit the skin and triggers vitamin D synthesis. Now there are some barriers to vitamin D absorption. The ultraviolet rays cannot penetrate sunscreen. Sunscreen is a necessity to protect us from developing skin cancer. Older folks are not as efficient at absorbing and synthesizing vitamin D. This finding presented a whole new line of research that looked at the relationship of low vitamin D levels in older people and impaired memory. David Llewellyn, a neuropsychologist out of the University of Exeter in England, found that poor performance on tests for memory and attention was about 42% higher for the group that was vitamin D deficient. Poor test results were nearly 400% higher in people with severe vitamin D deficiencies. This study did not prove that low vitamin D levels caused dementia but showed that the risk of developing dementia was markedly increased.
The researchers believe that vitamin D is important to brain health by protecting the blood supply to the brain. They also believe that vitamin D clears toxins that accumulate in the brain. A more recent study confirmed the link between vitamin D deficiency and dementia. They found that a wide variety of brain tissue has vitamin D receptors and when they are activated by vitamin D they facilitate nerve growth in the brain. It is believed that there is a boost in important brain chemicals and that there was an increase in effectiveness in glial cells nursing neurons back to health. The authors of this study concluded that “Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer’s disease.” (Science Daily, 2014)
Since the numbers of older people with vitamin D deficiency can be as high as 95%, there has to be some education on ways to increase levels of this vitamin. A general rule for sun exposure is to expose large amounts of bare skin to the sun just until it turns pink. This normally occurs in about half the time it would take you to burn. So if you burn in 30 minutes you want to have a 15 minute sun exposure about three times per week. Now if you are susceptible to skin cancer then this isn’t the safest way to get Vitamin D. There are foods , although few, that contain vitamin D: flesh of fatty fish (salmon, tuna, mackerel) and fish liver oils; small amounts of beef liver, cheese and egg yolks; fortified foods – milk cereal, some orange juice, yogurt and margarine (packaging of these products indicates if it has been fortified with vitamin D). Then there are supplements Vitamin D2 and D3. Either of these forms are a viable choice for vitamin D supplementation. Remember that the body would prefer to get nutrients through diet and sometimes has difficulty metabolizing supplements.
There is still some debate over vitamin D deficiencies. Did they occur as a function of aging or as a result of illness? It is still not clear if raising the level of vitamin D will help lessen cognitive issues. There are many risk factors for developing dementia and vitamin D deficiency has a firm place on that list.
Dr. Mercola. (November 6, 2014). Link between vitamin D deficiency and dementia confirmed. Retrieved April 29, 2015 from http://articles.mercola.com/sites/articles/archive/2014/11/06/vitamin-d-deficiency-dementai.aspx
National Institute of Health. Vitamin D – health professional fact sheet. Retrieved April 30, 2015 from http://ods.od.nih.gov/healthprofessionalfactsheet/VitaminD-Health-professional-fact-sheet
Simon, N, (July 13, 2010). Vitamin D deficiency linked to dementia. Retrieved August 26, 2010 from http://www.aarp.org/health/conditions-treatments/info-07-2010/vitamin_d_deficiency_linked_to_dementia