Both medical journals and the popular press over the last several years have been replete with information about the adverse health risks associated with insufficient vitamin D. Low levels of vitamin D have been linked with an increased risk for cardiovascular disease[1], diabetes[2], certain cancers[3], osteoporosis, autoimmune diseases, obesity, multiple sclerosis[4] and chronic pain.[5]
Cardiometabolic disorders impact the heart and vascular system as well as type 2 diabetes. Common risk factors among the variety of related disorders include high blood pressure, altered glucose metabolism, obesity and an abnormal lipid profile. A recent meta-analysis found a significant association between high levels of vitamin D and a reduction on the risk of having cardiovascular disease (33% reduction compared to low levels of vitamin D), type 2 diabetes (55% reduction) and metabolic syndrome (51% reduction).[6]
Although the specific mechanisms underlying these associations remains unclear, some studies have suggested that vitamin D may directly modulate gene expression through activation of vitamin D receptors.[7] Its effect on the regulation of intracellular and extracellular calcium may also play a role.
Recent data has demonstrated that nearly 80% of the US population is deficient in vitamin D, and that number is twice as many as were identified 10 years earlier in a previous survey.[8] This finding was surprising since our bodies are able to produce sufficient vitamin D provided we get adequate sun exposure. But most of us don’t get enough direct sunlight to fulfill our vitamin D requirements because of concerns about skin cancer and skin damage, less time spent outdoors and low light quality in winter in the northeast. Keep in mind that sunscreens greater than spf 8, cloudy days, clothing and glass block the sun’s ability to aid in the manufacture of vitamin D. Things are compounded for older individuals and those with darker, pigmented skin.
Vitamin D deficiency has become so prevalent that everyone should consider themselves at risk. A simple blood test can determine the amount of vitamin D circulating in your blood. A more sophisticated test can determine the intracellular concentration of this essential nutrient. It is, after all, the concentration within the cell that really matters. This test, called Micronutrient Testing from Spectracell Labs, is available at Alternity Healthcare.
What should you do if your vitamin d level is low? The best food sources of vitamin D are fatty fish like salmon, tuna mackerel or sardines. Vitamin D supplements are probably a good idea for most. My recommendation is 1000 – 2000 IU daily for maintenance. Higher doses would be required to raise a deficient level into the optimal range.
[1] Wang T, Passina M, et al. Vitamin D Deficiency and Risk of Cardiovascular disease. Circulation. 2008;117:503-511.
[2] Pittas A, Lau S. The Role of Vitamin D and Calcium in Type 2 Diabetes. A Systematic Review and Meta-Analysis. The Journal of Clinical Endocrinology & Metabolism Vol. 92, No. 6 2017-2029
[3] Jenab et al. Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations:a nested case-control study. BMJ, 2010; 340 (jan21 3)
[4] Ramagopalan SV, Maugeri NJ, Handunnetthi L, Lincoln MR, Orton S-M, et al. “Expression of the Multiple Sclerosis-Associated MHC Class II Allele HLA-DRB1*1501 Is Regulated by Vitamin D.” PLoS Genetics 2009, 5(2): e1000369
[5] Turner M, Hooten WM, et al. Inadequate Vitamin D Levels Linked To High Use Of Narcotic Medication By Patients In Chronic Pain. Mayo Clinic Proced March 209.
[6] Parker J, Hashmi O, et al. Levels of vitamin D and cardiometabolic disorders: Systematic review and meta-analysis. Maturitis, vol 63, issue 3, Pages 225-236 (March 2010)
[7] ScienceDaily. Study Shines More Light On Benefit Of Vitamin D In Fighting Cancer. Retrieved April 18, 2010, from http://www.sciencedaily.com /releases/2007/08/070821163248.htm
[8] Ginde A, Liu M, Camargo C, et al. Demographic Differences and Trends of Vitamin D insufficiency in the US Population, 1988 – 2004. Arch Intern Med. 2009;169(6):626-632
