Vitamin D and Pain
Vitamin D, Pain, and Migraine
Do you think you have normal Vitamin D levels? The answer might surprise you. Up to 36% of otherwise healthy adults aged 18-29 have a vitamin D deficiency, and 41% of outpatients age 49 and over. In hospitalized patients, the numbers are even higher: 56% of inpatients in the US, and 70-100% of hospital patients in Europe. Women are more likely than men to be deficient in vitamin D. Low vitamin D levels were first associated with pain some years ago, when rheumatologists made an association with joint pain and low vitamin D in arthritis patients. Since then, further study of vitamin D levels has led to an association with a number of other conditions, one of which is migraine.
Sources of Vitamin D
The primary source of vitamin D is synthesis in the skin after sun exposure. Darkly pigmented skin acts as a natural sunblock to this process, and can place an individual at increased risk of vitamin D deficiency. Risk groups for vitamin D deficiency include breastfed infants, older adults (50 and older), individuals with limited sun exposure, people with dark skin, people with fat malabsorption, such as Crohn’s disease or celiac disease, and people who are obese. Obesity constitutes a risk factor because it is thought that vitamin D is pooled in body fat. (Vitamin D is a fat-soluble vitamin.) When it is pooled in fat, it is less available to the bloodstream and the other places in your body that it needs to be active. Dietary sources of vitamin D are somewhat limited, and include fatty fish, such as salmon, tuna, mackerel, and sardines. Other food sources of vitamin D are egg yolks, fortified milk, beef liver, cod liver oil, fortified margarine, and swiss cheese. Some medications can interfere with vitamin D absorption, such as anticonvulsants, steroids, and non-statin cholesterol-reducing medications. Vitamin D is necessary for the proper absorption of calcium, and is important for proper bone metabolism and muscle function.
Vitamin D Deficiency and Pain
Vitamin D deficiency can cause nonspecific muscle weakness and widespread pain. This can result in chronic widespread pain and fatigue, and may result in a misdiagnosis of either fibromyalgia or chronic fatigue syndrome. If you have been diagnosed with either of these, and have not had a vitamin D level checked, talk to your doctor. Although preliminary, there is also some evidence to suggest that adequate vitamin D levels may also be protective against certain cancers and possibly, multiple sclerosis. But don’t just start taking supplements without knowing what you’re doing—get your level checked. It is possible to get too much vitamin D. All fat-soluble vitamins can cause toxicity if taken in excess.
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- Atherton K, Berry DJ, Parsons T, Macfarlane GJ, Power C, Hypponen E. Vitamin D and chronic widespread pain in a white middle-aged British population: evidence from a cross-sectional population survey [Internet]. Ann Rheum Dis. 2008 Aug 12;ard.2008.090456.[cited 2009 Apr 21]
- Holick, MH. High Prevalence of Vitamin D Inadequacy and Implications for Health. Mayo Clinic Proceedings [Internet]. 2006 Mar 1; 81(3):353-373.[cited 2009 Apr 21]
- Yetley EA. Assessing the vitamin D status of the US population [Internet]. Am J Clin Nutr. 2008 Aug 1;88(2):558S-564.[cited 2009 May 11] Available from: http://www.ajcn.org/cgi/content/abstract/88/2/558S