Cervical cancer Patient friendly summary

 Cancer cell.

Vitamin D levels above 40 ng/mL (100 nmol/L) may reduce the risk of cervical cancer.

Cervical cancer starts on the surface of the cervix. This is the lower part of the uterus (womb), which opens at the top of the vagina.

Cervical cancer affects 12,700 women in the United States annually and kills 4,300.

Risk factors

There are two major risk factors for cervical cancer:

  • Human papilloma virus (HPV)
  • Smoking, especially in combination with HPV. Smoking weakens the tight junctions of surface cells and allows HPV to invade. Smoking also lowers vitamin D blood levels.

Women who eat more fruit, vegetables, and fiber have a lower risk of developing cervical cancer.

Sunlight exposure and cervical cancer risk

Several studies show a connection between lack of sunlight exposure and cervical cancer risk.

One U.S. study and two studies in China came to the same conclusion - they found a reduced risk of cervical cancer incidence and/or mortality rate due to UVB exposure. In Germany, lower cervical cancer rates and higher skin cancer rates were noted in the highest winegrowing region compared to the region with the least winegrowing region.

Vitamin D and cervical cancer

Vitamin D levels

In Japan, researchers found a lower rate of invasive cervical cancer and higher vitamin D intake in nonsmokers. This was not true for smokers, however. Smoking reduces the amount of vitamin D in the blood.

How vitamin D works

Vitamin D has been shown to block the growth of cancer tumors. Vitamin D is processed by the liver. The body then produces calcitriol, an 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. In addition, calcitriol helps keep the surface layer of organs intact. This reduces the likelihood that cancer cells can invade the organ.


Based on the studies reviewed here, it appears that vitamin D may reduce the risk of cervical cancer. The effects are better for nonsmokers than smokers. Smokers would likely have to have higher vitamin D intake or production to receive the same benefits as nonsmokers.

Based on results for other cancers, vitamin D levels in the 40–60 ng/mL (100–150 nmol/L) range may provide reasonable protection. 


There might be a role for vitamin D in treating cervical cancer. But more research is needed. Based on studies of other cancers, women with cervical cancer might have a better prognosis when using vitamin D.

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 cervical cancer.

Page last edited: 08 August 2011