Findings from the Calcium and Vitamin D trial (CaD) component of the Women's Health Initiative (WHI) are being released in the upcoming "New England Journal of Medicine" (NEJM). Emory University is one of 40 sites that participated in the WHI trials. Emory investigators and WHI study participants are available for comment on the articles.
The intervention for CaD was designed to test whether supplementation with calcium and vitamin D would reduce the incidence of bone fractures in postmenopausal women. The researchers also tested whether supplementation would reduce the incidence of colorectal cancer.
Participants were recruited from eligible women already participating in either the hormone replacement therapy or dietary modification components of the WHI. A total of 36,282 postmenopausal women, age 50 to 79, were enrolled and followed for 7-10 years.
NEJM article summaries and Emory experts available for comment are listed below:
CALCIUM PLUS VITAMIN D SUPPLEMENTATION AND THE RISK OF FRACTURES Participants were randomly assigned to receive either a placebo, or 1000 mg of calcium carbonate with 400 IU of vitamin D3 daily. A small, but significant improvement in hip bone density was shown in healthy postmenopausal women, measuring 1.06 percent higher than the placebo group. However, the supplementation did not significantly reduce hip fracture, and it also increased the risk of kidney stones.
CALCIUM PLUS VITAMIN D SUPPLEMENTATION AND THE RISK OF COLORECTAL CANCER The study was conducted as a randomized, double-blind, placebo-controlled trial. Of the total recruits participating in this component, 18,176 women received 500 mg of calcium carbonate with 200 IU of vitamin D3 twice daily, and 18,106 received a matching placebo. It was concluded that daily vitamin D with calcium supplementation had no effect on the incidence of invasive colorectal cancer among postmenopausal women.
Emory investigators available for comment on the NEJM reports include:
Lawrence S. Phillips, MD -- Dr. Philips is the principal investigator for the WHI study being conducted at the Emory University School of Medicine. He is a professor of medicine in the division of endocrinology.
Ora Strickland, PhD, DSc (Hon.), RN, FAAN -- Dr. Strickland is a professor in the department of family and community nursing at the Nell Hodgson Woodruff School of Nursing. Dr. Strickland's research focuses primarily on measurement as well as perinatal health, women's health, and minority health issues. She is a co-principal investigator for the WHI at Emory University.
Nanette Wenger, MD -- Dr. Wenger is a co-investigator for the WHI at the Emory University site. She is a professor of medicine in cardiology at the Emory University School of Medicine.