Multiple myelomaPatient friendly summary

  • UVB light from the sun does not appear to reduce multiple myeloma risk.
  • Vitamin D may have a limited effect in increasing survival and physical well-being for those diagnosed with multiple myeloma.

Multiple myeloma (MM) is a cancer of the plasma cells. They are white blood cells that normally produce antibodies.

Multiple myeloma affects about 20,000 in the United States each year and kills about 11,000.

Risk factors

Risk factors of multiple myeloma may include:

  • Obesity
  • Diet, with fruit and vegetable consumption associated with reduced risk
  • Environmental toxins (radiation, hydrocarbon chemicals)

Multiple myeloma occurs twice as often in African-Americans than in white Americans.

Sunlight exposure and multiple myeloma risk

There is evidence that solar ultraviolet-B (UVB) light reduces the risk of multiple myeloma. Several geographical studies found reduced rates of multiple myeloma in regions with higher solar UVB doses. Also, a study of teachers in California found greatly reduced risk of multiple myeloma for those living in regions of higher UVB doses.

Vitamin D and multiple myeloma

Vitamin D levels

There is limited information on the benefits of vitamin D and multiple myeloma risk. According to two U.S. studies:

  • People with more advanced cases of multiple myeloma at time of diagnosis had lower vitamin D levels. However, people with advanced multiple myeloma may spend more time indoors and therefore have less sun exposure.
  • A Harvard study of U.S. doctors found a slightly reduced risk of multiple myeloma for those with higher vitamin D levels.

How vitamin D works

Multiple myeloma causes an increased production of matrix metalloproteinases (MMPs). MMPs are enzymes that enable cancer cells to migrate into other tissues. The hormonal version of vitamin D, calcitriol, reduces MMP production and the ability of cancer to spread.


High levels of vitamin D are associated with a lower risk of multiple myeloma in both observational studies of individuals and geographic studies of populations. 


Multiple myeloma is considered incurable. A study in Baltimore, Maryland, found no link between vitamin D level and multiple myeloma activity. However, in 10% to 20% of patients with multiple myeloma, vitamin D supplements reduced muscle weakness, fatigue, and chronic bone pain.

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 multiple myeloma.

Page last edited: 05 August 2011