Vitamin D and Calcium associated with increased colon cancer - another poorly edited abstract

A diet and cancer idea of which BrooklynDodger was unaware is that calcium and vitamin D prevent [or in epidemiologese, are negatively associated with the risk of] colon cancer. The publication abstracted below mines a mother lode of health data, the Women’s Health Study.

Paraphrased abstract:

The WHS in 1993 enrolled 39,876 women aged 45 or more and free of cardiovascular disease and cancer. This study reports on colon cancer observed over an average follow-up of 10 years. In that time, 0.55% of the women developed colorectal cancer [Dodger hasn’t read full text, assumes these are incident cases. Not very many cases, considering colon is in the top 3 cancer sites.] Based on diet questionnaires, a 20% increase in colon cancer, comparing highest quintile for calcium to the lowest, and a 34% increase for colon cancer for vitamin D intake were not significant. The investigators concluded the “Data provide little support for an association of calcium and vitamin D intake with colorectal cancer risk.”

Both the reviewers and the editor get demerits for a confusing and misleading abstract.

BrooklynDodger confesses that at first reading, the Dodger thought the authors were saying there was an improvement in experience that didn’t achieve significance. The Dodger was forced to go to the full text, to confirm that rates were higher in the expected protected group. The increased risk associated with Vitamin D was marginally significant – p <>

American Journal of Epidemiology 2005 161(8):755-764

Intakes of Calcium and Vitamin D and Risk of Colorectal Cancer in Women

Jennifer Lin1, Shumin M. Zhang1,2, Nancy R. Cook1,2, JoAnn E. Manson1,2,3, I-Min Lee1,2 and Julie E. Buring1,2,4 1 Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA2 Department of Epidemiology, Harvard School of Public Health, Boston, MA3 Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA4 Department of Ambulatory Care and Prevention, Harvard Medical School, Boston, MA

Correspondence to Dr. Jennifer Lin, Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, 900 Commonwealth Avenue East, Boston, MA 02215 (e-mail: jhlin@rics.bwh.harvard.edu