Vitamin D versus cancer

By Dr. Philip S. Chua

THE ROLE of vitamin D as a cancer-preventing and fighting agent has been on the forefront of medical news these days. Medically known as calciferol, this vitamin was discovered in 1918, in cod liver oil, and popularly called today as the Sunshine Vitamin (HTH column, Cebu Daily News, 7-27-06).

New studies revealed that “vitamin D regulates cell proliferation and can hold in check the sort of wild cell growth that leads to cancer.”

Several studies showed that among people taking high dose of vitamin D there was a decrease in the rate of at least 18 types of cancer and autoimmune diseases, including diabetes, rheumatoid arthritis, and 40% less risk for multiple sclerosis. Statistical analysis estimates that “thousands of caner deaths could be avoided in the United States each year if everyone gets enough vitamin D.”

Vitamin D is the only vitamin humans can produce on their own, when exposed to the ultraviolet B from the sun. In 15 minutes, a fair-skinned person, outside on a sunny day, can generate as much as 10,000 to 20,000 IU of vitamin D. This vitamin is recently in the limelight for being a “blockbuster” nutrient that confers even greater health benefits than previously recognized by the medical community. This “re-discovery” has put vitamin D in an altogether new perspective and importance.

Which vitamin D is preferred?

Vitamin D3 (choleciferol) is the recommended form since it is better absorbed and better utilized by the body compared to vitamin D2 (ergocalciferol).

What foods contain vitamin D?

Not many foods contain vitamin D. Milk is fortified with 125 IU of vitamin per glass. The following contain some vitamin D, but in themselves, do not provide the minimum daily requirement: organ meats, eggs, fish like tuna, mackerel, sardines, salmon, and herring. Having a balanced diet with enough calcium (1000-1500 mg) and vitamin D (400 IU daily) will prevent osteoporosis (thinning of the bones, a common cause of fractures). Exposure to the sun for about 5-10 minutes, 2-3 times a week is enough help in the body’s production of vitamin D.

How different is D from the other vitamins?

Besides being unique in the sense that it is the only vitamin our body can make on its own, vitamin D is also the only vitamin that influences the entire body, as the findings have shown. Receptors that respond to vitamin D have been discovered in almost all the various kinds of human cells, from the brain to the bones.

What else is vitamin D good for?

Besides the old role vitamin D was popular for (boosting absorption of calcium which is essential for bone health), vitamin D has also been found over the past decades to have a broad range of added benefits. This includes the ability to help fight cancers and diabetes. Sixty-three independent studies showed that high normal level of vitamin D reduced the risk of developing colon, breast and ovarian cancer by 50 percent. It is also a “pivotal feedstock” for a hormone that protects muscles, and inhibits autoimmune diseases like multiple sclerosis, lupus and inflammatory bowel illnesses. It also helps in easing some body aches and pain.

Can the anti-cancer properties of vitamin D be isolated?

Since it has been proven that the higher the dose of vitamin D, the greater its anti-cancer effect is, and since taking high doses of vitamin D might lead to elevation of the blood calcium to a toxic level, it would be ideal of the anti-cancer properties of vitamin D was separated from its other functions and effects. A promising reports on this issue comes from Georgetown University’s Lombardi Comprehensive Cancer Center, as published in the journal Molecular Cell.

“We found that we might be able to separate the two functions at the molecular level, and this raises the possibility that vitamin D can be chemically modified into a drug that will only have anticancer effects,” said Professor Stephen Byers, Ph.D., who, with Salimuddin Shah, Ph.D., spearheaded an international group of scientists in this research.

How does one prevent vitamin D deficiency?

Health education and awareness are essential. Human breast milk does not have enough vitamin D (40 IU/L), unlike fortified cow’s milk (400 IU/L). Babies who are breastfed should have a physician’s advice for possible oral supplement of vitamin D (300 IU per day) from birth to 6 months, Dr. Michael F. Hollick of the Boston University School of Medicine stated in their NIH-funded study, which involved 16,500 subjects, they have “found that lactating women need about 6,000 IU a day to transfer enough vitamin D into their milk to supply adequate amount to a nursing infant.” In more urgent cases, like the studies done among adolescents in the Far East, one does of intramuscular injection of 2.5 mg (100,000 IU) of ergocalciferol given in the Fall has increased the plasma level of vitamin D that lasted till Spring the following year.

Experts now say that, together with normal sun exposure, 1,000 IU is the amount of vitamin D3 tablet we all should be getting daily. While researches have also shown the safety of the daily intake of up to 2,000 IU, studies are still underway to determine if the intake of 5,000 IU daily is better, is safe, and is devoid of the potential toxic side-effect (dangerous increase of blood level of calcium). I strongly recommend that you check with your physician first before starting yourself on this regimen.

The wonders of science are indeed amazing. They alone are not enough to ward off diseases, like hypertension, arthritis, diabetes, heart disease, stroke, etc. We still have to do our share by not abusing our body with an unhealthy diet of saturated fat and high carbohydrates, lack of exercise, smoking, and alcohol and/or drug abuse, and lack of stress reduction program (R&R, mini-vacation).

There is, indeed, no substitute for a healthy lifestyle to maintain good health and maximize a happy and rewarding longevity.