What are the benefits of Vitamin D?
Vitamin D has many good reasons for us to sing its praises. It ‘s most famous for helping our bodies absorb calcium and phosphorous, which in turn helps us create strong bones and decrease osteoporosis risk. Additionally, vitamin D is now thought to decrease risk for autoimmune disease, cancer, diabetes, hypertension and even weight loss. It’s no wonder that its possible impact on Alzheimer’s disease is now being looked at.
How does Vitamin D impact Alzheimer’s Disease?
One study (Neurology, 2014) looked at blood samples of elderly adults who had participated in the US Cardiovascular Study. They compared groups with average, deficient and severely deficient vitamin D levels. Follow-up blood tests were looked at and the findings were significant, concluding that “vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease”.
Another study (Journal of Alzheimer’s Disease, 2014) looked at whether vitamin D3 has a neuroprotective role in diseases such as Alzheimer’s. Researchers found a very interesting relationship between brain pericytes (cells that wrap around the outside of our capillaries) and vitamin D. Brain pericytes respond to vitamin D by regulating the genes that help control neuroinflammation. Additionally, these pericytes respond to inflammation by triggering a chain reaction that results in more vitamin D being made! Even mild decreases in vitamin D3 resulted in significant increases in beta-amyloid, the chief culprit in plaques associated with Alzheimer’s disease (Journal of Neurodegenerative Diseases, 2014). Lastly, vitamin D was found to even help slow down progression of Alzheimer’s disease. Researchers have found that Alzheimer’s patients being treated with vitamin D were slower to progress from mild to moderate or severe disease compared to those who weren’t taking vitamin D (Vertex, 2014).
Vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease.
How do we get Vitamin D from the sun?
The majority of vitamin D we get happens when we expose our skin to the sun’s UVB rays. The amount of UVB we need is usually quite short but can be longer depending on our skin type. Melanin determines how light or dark our skin is and also determines how much vitamin D we can make. Think of melanin as nature’s sunscreen…the more you have of it, the less you burn. However, if melanin decreases UVB’s impact on the skin, it also decreases the vitamin D being created from those same UVB rays. People with fair skin tend to create vitamin D faster in the sun and those with darker skin usually need more time. Also, sunscreen will block UVB rays so allowing a short time outside (15 minutes/day) without sunscreen is often recommended for most healthy people. Other factors that influence vitamin D production are frequency in the sun, surface skin exposed (head vs. back), time of day and time of year.
How much is ideal?
The DRI, or Dietary Recommended Intake advises a daily allowance of 400 IU/day up to 800 IU/day, with UL (tolerable upper limits) going higher, depending on the age and specific health requirements. Ways to increase vitamin D in our diet include fish liver oil, the flesh of fatty fish (salmon, mackerel, albacore, etc.) and to a lesser degree, egg yolks, cheese. Most of the vitamin D we get through the diet comes from fortified products such as fortified cereals, milk, soy, etc.
How do I know if I’m deficient?
The best way to find out your vitamin D level is to take a blood test called 25(OH)D. The results will identify if your vitamin D status is very low, somewhat low, ideal or high. It is important to make sure any supplementation is in the ideal range for you, based on age, health and blood test results. There may or may not be a charge for this test, depending on where you live.
Is there ever too much of a good thing?
As mentioned earlier, vitamin D helps get calcium and phosphorous into the bones to harden them but excess vitamin D can help harden other things we don’t want hardened. Excessively high levels of vitamin D can have a negative impact on the cardiovascular system and the kidneys. As always, make sure you check with your health care provider to make sure any supplementation is ideal and appropriate for you.
About the author