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The Relationship between Vitamin D Levels & Rheumatoid Arthritis

Vitamin D, coined the “Sunshine vitamin”, is a group of fat soluble prohormones that play a critical role in regulating calcium and phosphorus levels in the body. Not technically a vitamin since sunlight triggers its synthesis in skin, vitamin D is a secosteroid. Vitamin D is considered the most important secosteroid in the body because it directly regulates genes. Therefore, deficiencies or insufficiencies can have a significant harmful impact on health.

Reduced vitamin D intake has been linked to increased susceptibility to the development of rheumatoid arthritis (RA) along with a number of other conditions. RA is an inflammatory arthritis that often leads to destruction of joint cartilage and fusion of the joints. It has been found that women who consume the recommended daily amount of vitamin D or more were 30% less likely to develop rheumatoid arthritis.1

One in three Canadians has insufficient vitamin D levels for bone health.2 The minimum vitamin D level required for optimal health is in the range of 75 to 100 nmol/L.3 In Canada, limited sun exposure means no vitamin D is produced in skin from November to April and taking the recommended daily amount (RDA) of vitamin D every day does not necessarily mean you will reach an optimum level. 4 By working with your healthcare professional, you can reach and maintain a vitamin D level within the optimum range to help mitigate your risk of arthritis along with other health conditions such as heart disease and cognitive impairment.


1. Merlino LA et al. Vitamin D intake is inversely associated with rheumatoid arthritis. Arthritis Rheum. 2004;50:72-77

2. Statistics Canada: Health at a Glance. Vitamin D blood levels of Canadians. Jan 2013. Catalogue 82-624-X

3. Bischoff-Ferrari HA, Giovanucci E. Willett WC et al. Am J ClinNutr. 2006;84(1):18-28.; Holick MF, Binkley NC, Bischoff-Ferrari HA et al. Clin Endocrin Metab. 2011:96(7):1911-30

4. Webb et al. Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. J Clin Endocrinol Metab. 1988 Aug;67(2):373-8.