Ovarian cancerPatient friendly summary

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

Ovarian cancer is cancer that starts in the ovaries. As it has few symptoms at first, it is often diagnosed at more advanced stages.

Each year, ovarian cancer affects approximately 22,000 women in the United States. It is one of the most deadly cancers and kills about 15,000 annually.

Risk factors

Ovarian cancer may be affected by a diet high in animal products. These foods have a lot of protein and fat, which increase the amount of growth factor. Growth factors help the body grow. They also help tumors grow. Dairy products such as milk may also be associated with increased risk of ovarian cancer.

Studies have shown that the risk of ovarian cancer may be lowered by:

  • Physical activity
  • Oral contraceptive use

Sunlight exposure and ovarian cancer risk

Ovarian cancer is one of the top 19 cancers sensitive to vitamin D. Several studies show that mortality rates for this cancer are lower in areas with more solar ultraviolet-B (UVB) light. This is similar to findings of other cancers including breast cancer.

A study from Spain on women living in different provinces and their sun exposure, especially in summer found women with more sun exposure had higher death rates from non-melanoma skin cancer. Interestingly, these women also had lower death rates from ovarian cancer. 

Vitamin D and ovarian cancer

Vitamin D levels

A study found that U.S. women with ovarian cancer were four times more likely to have low vitamin D blood levels than women without ovarian cancer. This study compared vitamin D levels greater than 23 ng/mL (58 nmol/L) to lower levels.

The rates of breast, colon, and rectal cancer decrease rapidly as vitamin D increases from very low values. The decrease in cancer rate then slows until vitamin D levels reach about 40 ng/mL (100 nmol/L), after which there is little further change. Comparable findings have not been reported for ovarian cancer. However, ovarian cancer may behave in a similar manner.

How vitamin D works

Vitamin D has been shown to block the growth of cancer tumors. Vitamin D3 obtained from solar UVB exposure or oral intake from food or supplements goes to the liver, where it is converted to calcidiol. From there, it goes to the kidney and other organs, where it can be converted to calcitriol as needed. Calcitriol is the hormonal version of vitamin D, which can activate vitamin D receptors and, thereby, affect the expression of many types of genes. 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. 


Studies compared the rates of vitamin D and breast, colon, and rectal cancers. Compared to low levels of vitamin D (below 20 ng/mL [50 nmol/L]), high levels (above 40 ng/mL [100 nmol/L]) may reduce the risk of these cancers by 15% to 25%. High levels of vitamin D may also increase survival after cancer diagnosis. These findings may also apply to ovarian cancer.

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

Vitamin D and calcium

Studies have shown that taking both vitamin D and calcium provides additional cancer protection for many types of cancer including ovarian cancer.

A study in Finland found that calcium and vitamin D may act independently to reduce the risk of ovarian cancer.

Calcium intake of more than 1000 mg/day from either diet or supplements is recommended.


There are no reported studies of using vitamin D to treat ovarian cancer. However, based on studies of vitamin D and other cancers, it seems likely that vitamin D would benefit those with ovarian cancer.

Those with ovarian cancer might consider taking up to 4000 IU (100 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 Ovarian Cancer.

Page last edited: 05 August 2011