The Many Functions of Vitamin D

It is well known that vitamin D is important for bone health. Vitamin D has a vast array of other functions important for overall good health. In fact, almost all tissues have vitamin D receptors which likely reflects its importance. 

Vitamin D is made when UV light from the sun comes into direct contact with our skin. We can obtain small amounts from foods such as fish, mushrooms and dairy products. Ultimately, to maintain healthy levels of vitamin D you have to have direct sun exposure. As we age, our ability to make vitamin D by our skin decreases, leading to increased rates of deficiency. Factors such as job and geographic location also commonly lead to deficiencies. We also live in environments and wear clothing that is designed to shield us from UV light, further complicating the situation. In these populations supplementation may be needed. 

Low vitamin D levels have been associated with many chronic disease such as hypertension, multiple sclerosis, dementia and depression. This may be a reason for the increased rates of depression during the dark winter months. In the elderly, low levels have been associated with increased number of bone fractures. One reason for this may be due to poor bone health or osteoporosis. However, researchers are now finding that deficient elderly have higher fall rates which is likely more significant reason for fractures. We still do not know exactly how vitamin D decreases fall rates but studies suggest that it may be due to its role in maintaining healthy brain function required for balance and coordination.

Although it is generally safe, it can build up in our tissues leading to toxic levels if taken for long periods of time or at high doses. Because of this, vitamin D levels should be checked by your doctor. Checking vitamin D levels will help determine the dose and severity of a deficiency.

Vitamin D research is a rapidly expanding and fascinating field. In future posts discuss the many other roles of Vitamin D in health and disease. 

Get your vitamin D levels checked now by Dr. Jeffery.

references

Annweiler, C., & Beauchet, O. (2014). Vitamin D in older adults: the need to specify standard values with respect to cognition. Frontiers in Aging Neuroscience, 6, 72. 

Annweiler, C., Karras, S. N., Anagnostis, P., & Beauchet, O. (2014). Vitamin D supplements: a novel therapeutic approach for Alzheimer patients. Experimental Pharmacology and Drug Discovery, 5, 6. 

Balion, C., Griffith, L. E., Strifler, L., Henderson, M., Patterson, C., Heckman, G., … Raina, P. (2012). Vitamin D, cognition, and dementia. Neurology, 79(13), 1397–1405. 

Bishnoi, R. J., Palmer, R. F., & Royall, D. R. (2014). Vitamin D Binding Protein as a Serum Biomarker of Alzheimer’s Disease. Journal of Alzheimer’s Disease: JAD. 

Kongsbak, M., von Essen, M., Levring, T., Schjerling, P., Woetmann, A., Odum, N., … Geisler, C. (2014). Vitamin D-binding protein controls T cell responses to vitamin D. BMC Immunology, 15(1), 35. 

Littlejohns, T. J., Henley, W. E., Lang, I. A., Annweiler, C., Beauchet, O., Chaves, P. H. M., … Llewellyn, D. J. (2014). Vitamin D and the risk of dementia and Alzheimer disease. Neurology, 10. 

Pludowski, P., Holick, M. F., Pilz, S., Wagner, C. L., Hollis, B. W., Grant, W. B., … Soni, M. (2013). Vitamin D effects on musculoskeletal health, immunity, autoimmunity, cardiovascular disease, cancer, fertility, pregnancy, dementia and mortality-a review of recent evidence. Autoimmunity Reviews, 12(10), 976–989. 

Schlogl, M., & Holick, M. F. (2014). Vitamin D and neurocognitive function. Clinical Interventions in Aging, 9, 559–568. 

Wobke, T. K., Sorg, B. L., & Steinhilber, D. (2014). Vitamin D in inflammatory diseases. Frontiers in Physiology, 5.