Vitamin D is a fat-soluble vitamin used by the body to regulate calcium levels and blood pressure, and it plays a role in immune system function. It also helps prevent uncontrolled cell division, which could lead to diseases like cancer. While there is a potential connection between vitamin D and cancer, a low blood level is not an indicator of cancer. Individuals with cancer are at greater risk of vitamin D deficiency as they tend to spend less time in the sun and treatments may cause a decline in consumption of foods that provide vitamin D.
Laboratory, observational, epidemiological, and randomized control trials have examined the possible association between cancer prevention and vitamin D intake. Lab studies found vitamin D did promote cancer cell death and prevented the cells from dividing. A randomized study originally looking at bone health, found postmenopausal women who took calcium and vitamin D supplements had a 60 percent lower risk of cancer. Observational studies found inconsistent results when looking at vitamin D intake and risk of colorectal and breast cancer.
Signs and Symptoms of Cancer
General signs and symptoms of cancer include unexplained weight loss, fever, fatigue, pain, skin changes, sores that will not heal, unusual bleeding or discharge, changes in bowel habits or bladder function and indigestion or trouble swallowing. Having any of these symptoms does not mean you have cancer as other issues can cause these same signs and symptoms. If you experience any of these problems, see your doctor.
Recommended Daily Intakes
The recommended daily allowance for vitamin D is between 600 and 800 international units per day. Linus Pauling Institute believes this level is too low and adults should take 2,000 IUs of supplemental vitamin D daily. Talk to your doctor before taking any dietary supplement.
Sources of Vitamin D
Most individuals get vitamin D from fortified foods such as milk, orange juice, yogurt and cereals, or from sun exposure. The skin produces vitamin D when exposed to ultraviolet radiation from sunlight. Some vitamin D is also in fatty fish, fish oil and eggs. Meat and cheese also contain small amounts.