Tips on getting vitamin D for cancer prevention

Breast cancer patients with low levels of vitamin D were much more likely to die of the disease or have it spread than patients getting enough of the nutrient, a study found - and certainly not a sunburn.

Vitamin D also is in certain foods and supplements, though the effectiveness varies. Here's the lowdown:

Q: How much sun should I get?

A: Many experts believe just 15 minutes a few times a week without sunscreen is sufficient and safe for most light-skinned people, but this is controversial.

Q: I'm black. Does my skin absorb enough ultraviolet rays to produce sufficient vitamin D?

A: In most cases, no. And some experts believe this may be one reason blacks have higher rates of cancer than whites. Nutrition specialists think vitamin D-3 supplements may be especially helpful for dark-skinned people. But you'll have to read the label to find D-3 — most multivitamins don't contain it.

Q: How much do I need?

A: Scientists think adults may need 1,000 international units (IUs) a day, possibly 1,500 for cancer prevention. The government says 2,000 IUs is the upper daily limit for anyone over a year old. Any more can cause the body to retain dangerous amounts of calcium.

Q. What about food sources?

A. Vitamin D is in salmon, tuna and other oily fish, and is routinely added to milk. But diet accounts for very little of the vitamin D circulating in blood.

Q: For years, we've been told to use sunscreen. Shouldn't we be worried about skin cancer?

A: Sunscreen is advised for longer periods outdoors, to prevent skin cancer. Skin cancer is rarely fatal. Melanoma, the deadliest kind, accounts for less than 2 percent of cancer deaths. The risks posed by other, more common cancers is far greater.