Vitamin D and endometrial cancer

New research indicates that low serum vitamin D may be associated with an increased incidence of endometrial cancer.

The November 16, 2007 issue of the journal Preventive Medicine reported an association between ultraviolet light exposure and a reduced risk of endometrial cancer. Two previous investigations have already linked a lower rate of kidney and ovarian cancer with greater UV exposure, which increases the formation of vitamin D3 in the body.

Researchers analyzed data made available through GLOBOCAN, a database of cancer incidence and mortality in 175 countries. In general, the incidence of endometrial cancer was highest at the highest latitudes in both hemispheres. The correlation between low UV exposure and low vitamin D levels and endometrial cancer incidence remained strong even after adjusting for variables such as fat intake, weight, cloud cover, skin pigmentation and others.

Most previous studies have focused on hormone levels and dietary fat intake and their role in the development of the disease. This is the first study linking low serum vitamin D levels to an increased risk of endometrial cancer. Along with other preventive measures, vitamin D adequacy should be considered as part of a comprehensive program for prevention of endometrial cancer.

Prev Med 2007 Nov;45(5):323-4.

Vitamin D supplementation lowers fracture risk

Researchers have found that doses of 700 to 800 IU of vitamin D3 per day may reduce the risk of hip fracture by 26 percent and nonvertebral fracture by 23 percent.

The May 11 2005 issue of the Journal of the American Medical Association published the results of a meta-analysis of 12 clinical trials involving vitamin D supplementation in the prevention of fracture. The analysis concluded that supplementation with higher than the commonly recommended 400 international unit (IU) doses of vitamin D reduces the risk of hip and nonvertebral fractures in older individuals.

The vitamin D studies included a total of 19,114 men and women aged 60 and older. The trials used the form of the vitamin known as cholecalciferol, or vitamin D3, which, according to studies cited in the current review, may be much more effective than the dietary form of the vitamin.

The researchers found that doses of 700 to 800 IU of vitamin D3 per day reduced the risk of hip fracture by 26 percent and nonvertebral fracture by 23 percent. Studies that used 400 IU vitamin D3 or less found no significant benefit for either type of fracture. The role of additional calcium supplementation could not clearly be defined from the studies, but it appears that at least 700 milligrams calcium per day may also be necessary for nonvertebral fracture prevention.

JAMA 2005 May 11;293(18):2257-64.