Low vitamin D levels mediate racial disparities in pain

Published on November 7, 2012 at 1:20 AM · No Comments

A new study reveals that black Americans display lower levels of vitamin D and greater pain sensitivity compared to white Americans. Findings published in Arthritis & Rheumatism, a journal of the American College of Rheumatology (ACR), indicate that vitamin D deficiency may be one of many factors that account for increased pain in older black Americans with knee osteoarthritis (OA).

Those with OA experience painful swelling and stiffness of the joints such as knees, hips and fingers. The National Arthritis Data Workgroup estimates that 27 million Americans over 25 years of age have OA (based on 2005 U.S. census data). A long-term study by researchers from the University of North Carolina-the Johnston County OA Project-suggests that lifetime risk of developing knee OA is roughly 46%.

During the last decade medical evidence has uncovered the importance of vitamin D, not only as a vitamin that aids in calcium absorption, but as a powerful hormone with numerous functions throughout the body. In fact, studies have found that a decreased vitamin D level reduces immunity and may contribute to diseases such as cancer and diabetes.

Most vitamin D in humans comes from exposure to the sun, with research suggesting that a deficiency of this important vitamin may be due to more indoor activities, increased sunscreen use, and need for longer sun exposure for those with dark skin pigmentation. One study estimates that 95% of black Americans compared to 70% of white Americans have low levels of vitamin D.

"People associate vitamin D with good bone health," said lead author Toni Glover, MSN, ARNP, a research nurse practitioner and doctoral candidate at the University of Florida, specializing in the study of pain in older adults. "Yet, not everyone is aware of what factors decrease vitamin D and how low levels could contribute to health issues, including chronic pain."

Clinical practice guidelines state that vitamin D levels less than 20 ng/mL represent deficiency and levels between 21 and 29 ng/mL represent insufficiency. Given that low levels of vitamin are linked to chronic pain and other health conditions, especially in black Americans, the research team set out to investigate if variations in vitamin D levels contribute to racial differences in patients with knee pain caused by OA.

With funding from the National Institute on Aging and the John A. Hartford Foundation and the Mayday Fund, researchers at the University of Florida and the University of Alabama at Birmingham recruited 94 participants-45 black and 49 white patients with symptomatic knee OA-to complete questionnaires regarding their symptoms. The study group was 75% female and had an average age of 56 years.

Read in | English | Español | Français | Deutsch | Português | Italiano | 日本語 | 한국어 | 简体中文 | 繁體中文 | Nederlands | Русский | Svenska | Polski
Comments
The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
Post a new comment
Post