Vitamin D deficiency has been linked to a wide range on health conditions, including rheumatic diseases. Three European studies looked into the relationship between rheumatism and vitamin D levels as well as the effect of vitamin D supplementation.
An Italian study followed up 1191 patients with rheumatoid arthritis. The results showed that vitamin D levels in the blood were lower in these patients compared to the normal levels of at least 50 nmol/L . Furthermore, supplementation does not always help. Only 40% of these patients who are take vitamin D daily supplementation of 800IU or more reach the normal values. The vitamin D levels in the blood in 60% of patients are still below normal. Measures of disease activity using questionnaires show that low vitamin D levels are correlated to increased disability, decreased mobility, and more swollen joints.
According to Dr. L. Idolazzi of the Rheumatology Unit, University of Verona, Italy:
“We have seen in studies that vitamin D deficiency is common in patients with a range of rheumatic diseases, and our results have confirmed this using several clinically accepted measures of disease activity. What we need to see now is a range of long term studies, which examine the clinical response of patients to vitamin D supplementation.”
In another Italian study, the effect of vitamin D supplementation on inflammatory autoimmune diseases was investigated. In this group of 43 patients, only 29% achieved normal vitamin D levels following supplementation.
A third study conducted in the UK involved 90 patients with rheumatoid arthritis, osteoporosis or unexplained muscle pain. These patients, too, had below than normal levels of vitamin D.
About vitamin D:
Vitamin D is also called the sunshine vitamin as it can only be synthesized by the body when exposed to sunlight. Unfortunately, vitamin D is not available in sufficient amounts in the food that we eat. Although vitamin D is available through sun exposure, the risk for skin cancer than the sun rays bring has led many health experts to discourage this practice.
In recent years, there has been a big debate about the necessity of vitamin D supplementation. In many countries, including the US, milk is supplemented with vitamin D. In addition, doctors often recommend vitamin D supplementation to their patients, especially little babies who are being breastfed. The American Academy of Pediatrics recommends routine vitamin D supplementation for children and updated its guidelines on Vitamin D intake last 2008. The new guidelines increased the recommended dose from 200 IU to 400 IU per day.