• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Johns Hopkins Arthritis Center

Show Search
Hide Search
  • Disease Information
    • Rheumatoid Arthritis
    • Psoriatic Arthritis
    • Ankylosing Spondylitis
    • Osteoarthritis
    • Gout
    • Osteoporosis
  • Patient Corner
    • Drug Information Sheets
    • Managing Your Arthritis
    • RheumTV – Patient Education Video Library
  • Our Research
    • Patient-Centered Outcomes Research
    • Current Research Studies
    • The Camille Julia Morgan Arthritis Research and Education Fund
  • About Us
    • Appointment Information
    • Contact Us
    • Our Faculty
    • Our Staff
    • Rheumatology Specialty Centers
  • Donate
Home / Arthritis News / Vitamin D Intake Is Inversely Associated With Rheumatoid Arthritis

Vitamin D Intake Is Inversely Associated With Rheumatoid Arthritis

April 13, 2005 By Arthritis Center

Vitamin D plays an important role in bone metabolism and may also have immunomodulatory effects. Specifically, it has been shown in animals that vitamin D can suppress the effects of autoimmunity. Although we do not know whether a similar effect would be found in humans, no studies have assessed the association between Vitamin D and rheumatoid arthritis (RA), a devastating autoimmune disease. To address this issue, Merlino and associates (Arthritis and Rheumatism, 50:72-77, 2004) analyzed data from a large prospective cohort of women aged 55-69 in 1986 who were followed for 11 years.

Methods:

To assess the association between vitamin D and RA, data on 29,368 women from the Iowa Womens Health Study (IWHS) were used. The IWHS is a population-based prospective cohort study initiated in 1986. Using a self-administered questionnaire the IWHS collects demographic data, medical and reproductive history, lifestyle factors, and a 127-item food frequency questionnaire that included supplement use. Vitamin D intake was estimated by calculating the vitamin D content of foods, as well as from the intake of vitamins and mineral supplements. Cox proportional hazards regression was used to estimate the association between vitamin D intake and RA incidence, adjusting for several factors including age, smoking, and hormone replacement therapy.

Results:

Through the 11 years of follow-up, 152 cases of RA were validated medically. Greater intake of vitamin D was associated with reduced risk of RA. That is, those with greater intake of vitamin D were 67% as likely to as those with lesser intake of vitamin D to have RA. This association was present for both dietary and supplemental vitamin D; however, vitamin D derived from supplements reduced the risk of RA to a greater extent than did vitamin D derived from the diet (66% vs. 72%).

Conclusions:

Greater vitamin D intake may associate with lower risk of RA in older women.

Editorial Comments:

Although there is a biological explanation for the observed association between vitamin D and RA (i.e., animal models suggest that vitamin D may be an immunosuppressant), this study was not hypothesis driven. Thus, it is possible, though unlikely, that chance alone may account for the observed association. Apart from this, there are several other considerations that may attenuate the studys findings. First, vitamin D intake was assessed only once in 1986. Although this assessment was prior to the development of RA, it is possible that in the intervening 11 years participants increased their vitamin D intake. Second, sun exposure, an important source of vitamin D, was not assessed and may represent an important unmeasured confounding variable. Finally, because the IWHS population was made up of predominantly white women, the results may not generalize to other groups of adults with RA. Although the immunomodulatory effects of vitamin D are unknown in humans, this study suggests that vitamin D may play a role in reducing the risk of immunologic disorders such as RA.

Receive the Latest News from Johns Hopkins Rheumatology

Receive the Latest News from Johns Hopkins Rheumatology

Join our mailing list to receive the latest news and updates from Johns Hopkins Rheumatology.

Interested In

You have Successfully Subscribed!

Arthritis Center

Founded in 1998, the Arthritis Center at Johns Hopkins is dedicated to providing quality education to patients and healthcare providers alike.

Use of this Site

All information contained within the Johns Hopkins Arthritis Center website is intended for educational purposes only. Physicians and other health care professionals are encouraged to consult other sources and confirm the information contained within this site. Consumers should never disregard medical advice or delay in seeking it because of something they may have read on this website.

Primary Sidebar

Recent News

Exercise Tips for Arthritis Patients

How Does Exercise Affect my Joints? How Frequently Should I Be Exercising? Should I Lose Weight for Exercise to be

Risks and Benefits of Biologic Medications

Victoria Ruffing, RN, BC, Director of Patient Education at the Johns Hopkins Arthritis Center, shares the risks and benefits of biologic for

How to Manage Rheumatoid Arthritis Flares

Through research, doctors have a clearer understanding of how flares can impact a patient on a personal and emotional level. Dr. Uzma Haque

Complementary & Alternative Medicines for Psoriatic Arthritis

There are many complementary & alternative medicines and practices that have been found to be beneficial in curbing arthritis pain,

I can’t be a runner because I have Rheumatoid Arthritis (RA), right?

Dr. Manno discusses running and Rheumatoid Arthritis. Is it an option for the RA patient?

News Categories

  • Ankylosing Spondylitis News
  • Fibromyalgia News
  • Gout News
  • Lupus News
  • Osteoarthritis News
  • Osteoporosis News
  • Psoriatic Arthritis News
  • Rheumatoid Arthritis News
RheumTV Logo

Rheum.TV is an informational platform created to educate patients living with a rheumatic disease. With over 100 disease education videos produced by the team at Johns Hopkins Rheumatology.

Visit Rheum.TV

Footer

Johns Hopkins Rheumatology

  • Johns Hopkins Rheumatology
  • Johns Hopkins Lupus Center
  • Johns Hopkins Lyme Disease Research Center
  • Johns Hopkins Myositis Center
  • Johns Hopkins Scleroderma Center
  • Johns Hopkins Sjögren’s Syndrome Center
  • Johns Hopkins Vasculitis Center

Connect With Us

  • Facebook
  • Twitter
  • YouTube

Johns Hopkins Medicine

© 2023 Johns Hopkins Arthritis Center
Patient Privacy