Vitamin D receptors are found all over the body, including the immune cells. Research has clearly shown that vitamin D deficiency is part of the seasonal nature of cold and flu outbreaks – less sunlight means less vitamin D, which leads to lower immunity and more illness.
One of the byproducts of vitamin D’s breakdown, called 1,25(OH)2D, enters muscle cells and affects the nucleus. Once there, the vitamin D metabolite enhances the cell’s contraction ability. Since muscles work by contraction and relaxation, a muscle’s ability to contract is essential to its strength and response to outside forces. Vitamin D, then, makes muscles stronger in a very direct way.
When it comes to being happy, the scientific evidence is clear. The lower your vitamin D levels, the more likely you are to feel blue rather than happy. Low levels of vitamin D have long been associated with a higher incidence of depression. Interestingly, when vitamin D3 supplements were compared to anti-depressants in a 2014 study, the positive effect of vitamin D3 on mood was comparable to the effects of the anti-depressants.
Weight Loss
When you don’t have enough vitamin D, you feel hungry all the time, no matter how much you eat. That is because low levels of vitamin D interfere with the effectiveness of leptin, the appetite hormone that tells you when you are full. When vitamin D is replenished and back to normal levels, leptin’s actions are restored, thus creating feelings of satiety and aiding in weight loss.
In the past few years, many studies have linked shortage of vitamin D with cognitive impairment in older men and women. Research has demonstrated that vitamin D has a variety of neuroprotective roles, including helping to rid the brain of beta-amyloid, an abnormal protein that is believed to be a major cause of Alzheimer’s disease. Additionally, an international study (the largest to date) shows that seniors with very low levels of vitamin D are at twice the risk of Alzheimer’s disease.