Vitamin D and Calcium Intake in Relation to Type 2 Diabetes in Women

  1. Anastassios G. Pittas, MD1,
  2. Bess Dawson-Hughes, MD12,
  3. Tricia Li, MD3,
  4. Rob M. Van Dam, PHD3,
  5. Walter C. Willett, MD, DRPH3,
  6. Joann E. Manson, MD, DRPH34 and
  7. Frank B. Hu, MD, PHD3
  1. 1Division of Endocrinology, Diabetes and Metabolism, Tufts-New England Medical Center, Boston, Massachusetts
  2. 2Bone Metabolism Laboratory, Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
  3. 3Harvard School of Public Health and Channing Laboratory, Boston, Massachusetts
  4. 4Division of Preventive Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
  1. Address correspondence and reprint requests to Anastassios G. Pittas, MD, Division of Endocrinology, Diabetes and Metabolism, Tufts-New England Medical Center, 750 Washington St., #268, Boston, MA 02111. E-mail: apittas{at}tufts-nemc.org

Abstract

OBJECTIVE—The purpose of this study was to prospectively examine the association between vitamin D and calcium intake and risk of type 2 diabetes.

RESEARCH DESIGN AND METHODS—In the Nurses’ Health Study, we followed 83,779 women who had no history of diabetes, cardiovascular disease, or cancer at baseline for the development of type 2 diabetes. Vitamin D and calcium intake from diet and supplements was assessed every 2–4 years. During 20 years of follow-up, we documented 4,843 incident cases of type 2 diabetes.

RESULTS—After adjusting for multiple potential confounders, there was no association between total vitamin D intake and type 2 diabetes. However, the relative risk (RR) of type 2 diabetes was 0.87 (95% CI 0.75–1.00; P for trend = 0.04) comparing the highest with the lowest category of vitamin D intake from supplements. The multivariate RRs of type 2 diabetes were 0.79 (0.70–0.90; P for trend <0.001) comparing the highest with the lowest category of calcium intake from all sources and 0.82 (0.72–0.92; P for trend <0.001) comparing the highest with the lowest category of calcium intake from supplements. A combined daily intake of >1,200 mg calcium and >800 IU vitamin D was associated with a 33% lower risk of type 2 diabetes with RR of 0.67 (0.49–0.90) compared with an intake of <600 mg and 400 IU calcium and vitamin D, respectively.

CONCLUSIONS— The results of this large prospective study suggest a potential beneficial role for both vitamin D and calcium intake in reducing the risk of type 2 diabetes.

Footnotes

  • A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

    The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

    • Accepted November 18, 2005.
    • Received October 13, 2005.
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