Vitamin D is one of the latest, greatest hot cancer topics. Why? Well, it seems many of us women are vitamin D deficient. Such a deficiency might be linked to breast cancer risk so it's in our best interest to make sure we get a healthy dose of this vitamin. It's not as easy as adhering to the Dietary Reference Intake (DRI) guidelines, though. Follow them and you'll still come up short -- the Food and Nutrition Board, responsible for setting the DRIs, have not yet updated guidelines in light of cancer concerns. So what's a girl to do?

For starters, we need to understand that for overall health benefits, 1,000 IU (International Units) per day are necessary. The outdated DRI recommends 200 to 600 IU. This is based on preventing only bone diseases like rickets. Second, keep in mind it's safe to take up to 10,000 IU each day. Third, up your intake of this important vitamin. Here's how:

Fatty fish is the best source of vitamin D. But watch out for high mercury levels. Fortified milk is also good. It has 100 IU of vitamin D per eight-ounce serving, but cow's milk been linked to breast cancer risk as well.

It's been suspected that taking too many vitamins may spike men's risk of dying from prostate cancer. On Wednesday, the biggest study yet to link high-dose multivitamins and prostate damage was published in the Journal of the National Cancer Institute.

Government scientists have been looking at the diet and health of almost 300,000 men. One third reported taking a daily multivitamin. Five percent were heavy users, marked by use more than seven times per week. Within five years of the study's launch, 10,241 men had been diagnosed with prostate cancer. About 1,476 had an advanced form of the disease. And 179 died.

It seems heavy multivitamin users were nearly twice as likely to get fatal prostate cancer as men who never took the pills. Yet, oddly, researchers found no link between multivitamin use and early-stage prostate cancer. It could be that vitamins have little effect until a tumor appears -- and then it spurs growth.

More studies are on the horizon for this topic, which is becoming more and more pressing.

Here's my problem with health-related advice and wisdom -- it's always changing. And I'm never sure if I'm buying into the right practice. Should I eat low-fat foods, for example, or should I stick with moderate amounts of regular food? Is red meat a good source of protein and other goodies or a direct path to breast cancer recurrence? Will sunscreen save my life or cause malignant lesions to develop on my fair skin?

How about drinking eight glass of water a day? Maybe yes. Maybe no, according to experts who say we get water from sources other than diet alone and while we do need to replace water lost through breathing, urination, and sweating each day, our lost fluids do not total 64 ounces. And it seems we can drink too much water. This can lead to an imbalance of sodium and a condition called hyponatremia.

Vitamin supplements? Eat a good amount of fruits, veggies, whole grains, low-fat dairy, protein, and the right amount of calories and you don't need a multivitamin. But most of us don't eat right. So we probably need one.

OK. Now breathe. Take it all in. Filter it. Use it. Abandon it. As for me -- I'm going with the tactic mentioned above several times -- moderation. Seems to me this approach is the key to both health and happiness.

Time to test your smarts -- about sleep, sun, food, and alcohol.

Just read the following questions, pick an option and then scroll down to determine if you really know what's best for your health.

• Is it healthier to sleep an extra hour or force yourself out of bed in the morning to exercise?

• Is it healthier to spend 15 minutes in the sun without sunscreen or two hours in the sun wearing SPF 30?

• Is it better to have a second glass of wine at dinner or a sinful dessert?

The evidence is stacking up. And it seems almost everyone will soon agree that exercising can help prevent a return of cancer for those who have already done battle with the disease.

The American Cancer Society just issued a report updating nutrition and physical activity recommendations for cancer survivors. Exercise tops the list of recommendations.

For some types of cancers, exercising for just one to three hours per week can lower the risk of cancer recurrence and death, as well as death from all causes. Exercise has also been shown to improve fitness, diminish fatigue, and boost quality of life for survivors.

The report also states that while a vegetarian diet may be healthful in some ways, there is no direct proof that the diet can prevent cancer recurrence. Survivors who do choose a vegetarian lifestyle should ensure they are receiving an adequate intake of nutrients.

A standard multivitamin and mineral supplement equivalent to 100 percent of the Daily Value can help survivors meet their nutrient needs when it's difficult to eat a healthy diet. Some supplements -- such as those high in folic acid or antioxidants -- may be harmful during cancer treatment.

According to the American Cancer Society, food safety is especially important for cancer survivors, especially during treatment that causes immunosuppression.

And then there's alcohol. Alcohol can affect the risk for new primary cancers and should be used sparingly -- or not at all.