Non-Hodgkin lymphomaPatient friendly summary

  • Sunlight has a direct effect on reducing the risk of non-Hodgkin’s lymphoma.
  • Vitamin D has been shown to block the growth and spread of cancer.
  • Vitamin D levels greater than 40 ng/mL (100 nmol/L) may reduce the risk of non-Hodgkin’s lymphoma.

Non-Hodgkin's lymphoma is cancer of the lymphoid tissue, which includes the lymph nodes, spleen, and other organs of the immune system.

Non-Hodgkin’s lymphoma is an important cause of disease and death. In the United States each year, the disease affects about 65,000 people and kills approximately 20,000.

Risk factors

There are many risk factors associated with non-Hodgkin’s lymphoma. The most important 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.
  • Alcohol consumption: Studies have shown a link between alcohol and this disease.
  • Obesity: Obesity is associated with a risk of non-Hodgkin’s lymphoma.
  • Environmental chemicals: Pesticides and air pollution have a direct effect on the risk of this disease.
  • Smoking: Smoking is also associated with a risk of non-Hodgkin’s lymphoma.

The risk of non-Hodgkin’s lymphoma is lowered by a diet high in vegetable products. This includes fruits, vegetables, grains, and beans.

Sunlight exposure and non-Hodgkin’s lymphoma risk

Sunlight has a direct effect on lowering the risk of many types of non-Hodgkin’s lymphoma. Ultraviolet-B (UVB) sunlight stimulates the body to produce vitamin D. Vitamin D may protect against the disease.

However, ultraviolet A (UVA) light may cause harm to the immune system. As a result, UVA may increase the risk of this disease. This is especially true in northern European countries, such as Sweden, where there is less UVB light.

The number non-Hodgkin’s lymphoma cases and resulting deaths vary with the amount of regional sunlight. According to studies of this disease, there are:

  • Lower rates in the sunny Southwest United States and higher rates in the darker Northeast
  • Higher rates in countries that are farther from the equator and receive less sunlight

Vitamin D and non-Hodgkin’s lymphoma

Vitamin D levels

Researchers in Finland studied male smokers and the effects of vitamin D on the risk of non-Hodgkin’s lymphoma. The men were 50–69 years of age at the start of the study. Seven years later, men with vitamin D levels greater than 24 ng/mL (60 nmol/L) had a 57% lower risk of developing the disease compared to those with levels less than 16 ng/mL (40 nmol/L).

The results of this study are similar to the results of other studies. The rates of breast, colon, and rectal cancers decreased rapidly as vitamin D levels increased from less than 10 ng/mL (25 nmol/L) up to 20–30 ng/mL (50–75 nmol/L). The cancer rates then decreased at a slower rate until vitamin D levels reached about 50 ng/mL (150 nmol/L).

How vitamin D works

Vitamin D has been shown to block the growth of cancer tumors. The hormonal version of vitamin D, called calcitriol, reduces the risk of cancer. 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.


Based on studies of breast, colon, and rectal cancer, vitamin D levels of 40–60 ng/mL (100–150 nmol/L) may lower the risk of non-Hodgkin’s lymphoma. 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.


People with higher vitamin D levels at the time of cancer diagnosis may have a higher survival rate. This is true for many types of cancer. These studies suggest that increasing vitamin D levels after non-Hodgkin’s lymphoma diagnosis would improve the chances of survival.

Some cancer treatment centers are now giving at least 5000 IU (125 mcg)/day vitamin D to patients with cancer. Outcome results have yet to be published.

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 non-Hodgkin’s lymphoma.

Page last edited: 06 May 2011