Study links vitamin D deficiency in black Americans to knee osteoarthritis

A recent report published in Arthritis & Rheumatism, the journal of the American College of Rheumatology, revealed that many black Americans may have a vitamin D deficiency, which could contribute to their increased levels of pain due to knee osteoarthritis (OA).

The study, which was funded by the National Institute on Aging, the John A. Hartford Foundation and the Mayday Fund, analyzed 94 subjects with symptomatic knee OA, 45 of whom were black and 49 of whom were white. The mean age of the group was 56 years old and 75 percent of the participants were female.

Patients filled out a questionnaire about their symptoms and a heat pain threshold test, which required patients to report when they first started to feel pain, along with a pain tolerance test in their knees and forearms which were affected by arthritis. The findings revealed that 84 percent of the black patients had a vitamin D deficiency. The study also found that black subjects had a greater levels of knee osteoarthritis pain and those who had lower vitamin D levels were also more sensitive to pain.

Although there appeared to be a correlation between race and pain threshold, lead author Toni Glover, M.S.N., A.R.N.P., of the University of Florida, noted that more research is needed to obtain conclusive evidence about the relationship between the two, and that subjects should talk to healthcare providers to find out how to increase their vitamin D levels.

“Our data demonstrate that differences in experimental pain sensitivity between the two races are mediated at least in part by variations in vitamin D levels,” said Glover. “However, further studies are needed to fully understand the link between low vitamin D levels and racial disparities in pain. Although rare, vitamin D toxicity is possible and older adults should consult with their primary care provider regarding supplementation. It may be warranted that older black Americans with chronic widespread pain be screened for vitamin D deficiency to reduce disparities in pain.”

Vitamin D sources and benefits
The Office of Dietary Supplements reports that vitamin D helps with calcium absorption and it aids bone growth. It also stimulates cell growth and boosts the immune system. People can get vitamin D from sun exposure, fortified cereal and a Skinny D supplement from Dr. Newton’s Naturals.