[Lani]

Study: Vitamin D reduces cancer risk [Associated Press]
OMAHA, Neb. - Building hope for one pill to prevent many cancers, vitamin D cut the risk of several types of cancer by 60 percent overall for older women in the most rigorous study yet.
The new research strengthens the case made by some specialists that vitamin D may be a powerful cancer preventive and most people should get more of it. Experts remain split, though, on how much to take.
"The findings ... are a breakthrough of great medical and public health importance," declared Cedric Garland, a prominent vitamin D researcher at the University of California-San Diego. "No other method to prevent cancer has been identified that has such a powerful impact."
While the most reliable yet, the study does have drawbacks. It was designed mainly to monitor how calcium and vitamin D improve bone health, and the number of cancer cases overall was small, showing up in just 50 patients.
"It's a very small study," said Dr. Edward Giovannucci, who researches nutrition and cancer at the Harvard School of Public Health. "I don't think it's the last word."
In either case, the study takes an important step in extending several decades of research that began with observations that cancer rates among similar groups of people were lower in southern latitudes than in northern ones. Scientists reasoned that had to do with more direct sunlight in southern regions.

ABSTRACT: Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial [American Journal of Clinical Nutrition]
Background: Numerous observational studies have found supplemental calcium and vitamin D to be associated with reduced risk of common cancers. However, interventional studies to test this effect are lacking.
Objective: The purpose of this analysis was to determine the efficacy of calcium alone and calcium plus vitamin D in reducing incident cancer risk of all types.
Design: This was a 4-y, population-based, double-blind, randomized placebo-controlled trial. The primary outcome was fracture incidence, and the principal secondary outcome was cancer incidence. The subjects were 1179 community-dwelling women randomly selected from the population of healthy postmenopausal women aged >55 y in a 9-county rural area of Nebraska centered at latitude 41.4 deg N. Subjects were randomly assigned to receive 1400-1500 mg supplemental calcium/d alone (Ca-only), supplemental calcium plus 1100 IU vitamin D3/d (Ca + D), or placebo.
Results: When analyzed by intention to treat, cancer incidence was lower in the Ca + D women than in the placebo control subjects (P < 0.03). With the use of logistic regression, the unadjusted relative risks (RR) of incident cancer in the Ca + D and Ca-only groups were 0.402 (P = 0.01) and 0.532 (P = 0.06), respectively. When analysis was confined to cancers diagnosed after the first 12 mo, RR for the Ca + D group fell to 0.232 (CI: 0.09, 0.60; P < 0.005) but did not change significantly for the Ca-only group. In multiple logistic regression models, both treatment and serum 25-hydroxyvitamin D concentrations were significant, independent predictors of cancer risk.
Conclusions: Improving calcium and vitamin D nutritional status substantially reduces all-cancer risk in postmenopausal women.