There are a myriad of factors that can contribute to pain that becomes chronic. These range from repeated overuse, catastrophizing or hypervigilance (psychological factors are a big one), and even nutritional deficiencies. One of the nutrient deficiencies that has been correlated with chronic pain is a deficiency in Vitamin D. Different studies have found percentages of people with chronic pain conditions to vary widely in their rates of Vitamin D deficiency ranging from 26% all the way up to 100% of certain populations (Plotnikoff and Quigley 2003; Turner et al. 2008).

Vitamin D assists many physiologic functions in the body; ranging from helping us absorb calcium, to assisting normal endocrine and immune system functioning. Our bodies can synthesize vitamin D through normal sun exposure, and also get it through diet and supplementation. Levels of vitamin D in the body are measured by looking at the circulating levels of 25 hydroxyvitamin D (25-OH-D). Values below 30 nmol/L indicate deficiency while levels between 30-50 nmol/L indicate insufficiency. An optimal level would be above 50nmol/L (Martin and Reid 2017). The normal intake values recommended are 600 international units per day, however the upper tolerable limit for individuals with deficiency according to the NIH is 4,000 IU/day (https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/#ref). In individuals with deficiency or with high chance of deficiency we typically recommend taking between 1,000 and 2,000 IU per day until blood levels are above 50nmol/L, in a subsequent blood test. If you are supplementing, it is important to supplement with companies that have a good reputation and are tested by third party organizations for purity and quality. There are not many instances of vitamin D toxicity, but those that are present are typically due to either chronic over supplementation (Ozkan et al. 2012) or labelling errors from the companies that make them (Araki et al. 2011).

It is crucial to recognize that Vitamin D alone is not effective enough as a sole intervention for chronic pain management. In spite of there being an established correlation between vitamin D and normal physiological functioning, we do not yet have the evidence necessary (or an established mechanism) to say that it is effective enough to be used alone (Martin and Reid 2017).That being said, there are some studies that have shown pain scores and function to be improved with vitamin D supplementation (Yong et al. 2017; Högberg et al. 2012). There is also preliminary data that vitamin D supplementation may enhance recovery, especially when individuals have deficient circulating levels of vitamin D (Heaton et al. 2017). Another aspect about vitamin D is that besides the cases cited above, there is very low risk to supplementation with vitamin D, especially when moderate doses with reputable sources are used.