Endometrial cancerPatient friendly summary

  • Endometrial cancer is one of the top 19 cancers sensitive to vitamin D.
  • Endometrial cancer mortality rates are lower in areas with more solar UVB light.
  • Vitamin D may reduce the risk of endometrial cancer by 15% to 25% and increase survival rates after diagnosis.

Endometrial cancer is cancer that starts in the endometrium, the lining of the uterus (womb).

Each year, endometrial cancer affects approximately 46,000 U.S. women and kills about 8000.

Risk factors

Risk factors for endometrial cancer include:

  • Diet high in animal products: Eating a lot of meat, especially early in life, causes the body to produce a growth factor. Growth factors help the body grow. They also help tumors grow. Dairy products contain estrogen, a hormone that increases growth factor.
  • Alcohol consumption: There is a link between alcohol and endometrial cancer.
  • Obesity: Obesity is associated with a risk of this cancer.
  • Hormone replacement therapy and estrogen: Either oral or body-produced estrogen increases the risk of this cancer.
  • Environmental chemicals: Pesticides and air pollution have a direct effect on the risk of endometrial cancer.
  • Smoking: Smoking is associated with a risk of this cancer.

The risk of endometrial cancer is lowered by:

  • Diets high in vegetable products such as fruits, vegetables, grains, and beans
  • Oral contraceptive use, which lowers estrogen levels.
  • Physical activity

Sunlight exposure and endometrial cancer risk

Endometrial cancer is one of the top 19 cancers that are sensitive to vitamin D:

  • Ultraviolet B (UVB) light may lower the death rates of women with endometrial cancer. This is also true of many other types of cancers.
  • In one Swedish study, women exposed to more UVB (while sunbathing or indoor tanning) had a 20% to 40% lower risk of endometrial cancer.

Vitamin D and endometrial cancer

Vitamin D levels

There have been several studies on vitamin D and endometrial cancer:

  • In a U.S. study, women with this cancer were four times more likely to have low vitamin D levels.
  • Other studies compared the effects of vitamin D and the rates of breast, colon, and rectal cancers. As vitamin D levels increased from low to high values, cancer rates decreased considerably.
  • Comparable findings have been reported for endometrial cancer, which may respond in a similar manner to vitamin D.

How vitamin D works

Vitamin D has been shown to block the growth of cancer tumors. The active form of vitamin D, calcitriol, provides numerous benefits against cancer. This form of vitamin D encourages cells to either adapt to their organ or commit apoptosis (cell suicide). Calcitriol also limits blood supply to the tumor and reduces the spread of cancer. 


High levels of vitamin D are associated with a lower risk of endometrial cancer.

Studies compared cancer risk in people with high (40–60 ng/mL [100–150 nmol/L]) and low (20 ng/mL [50 nmol/L]) vitamin D levels. The risk of breast, colon, and rectal cancer was reduced by 15% to 25% in women with high vitamin D levels. High levels may also lower the risk of endometrial cancer. High vitamin D levels may increase survival after cancer diagnosis.

Taking 1000–4000 international units (IU) (25–100 mcg)/day of vitamin D is generally required to reach blood levels of 40–60 ng/mL (100–150 nmol/L).

Vitamin D and calcium

Taking both vitamin D and calcium provides additional protection against many types of cancer. This may include endometrial cancer.

In one study, vitamin D and calcium acted independently to reduce the risk of endometrial cancer. Calcium intake of more than 1000 mg/day is recommended. This intake can be from either diet or supplements.


There are no reported studies using vitamin D to treat endometrial cancer. However, based on higher vitamin D levels and increased cancer survival rates, vitamin D may be beneficial for those with endometrial cancer.

Those with endometrial cancer might consider taking 5000 IU (125 mcg)/day of vitamin D3 (cholecalciferol) to raise blood vitamin D levels to more than 40 ng/mL (100 nmol/L).

Find out more...

Do you want to find out more and see the research upon which this summary is based?  Read our detailed evidence summary on Endometrial cancer.

Page last edited: 05 August 2011