To Your Health

In seventh-grade science class we all learned that if you don't get enough vitamin D, you get rickets. Bet you didn't know that too little D can also make you fat. A recent study of women in California found that the heavier women had lower levels of what is emerging as the vitamin world's superstar.

Recent research has linked D deficiency to a risk reduction for a mind-blowing range of ailments, from heart disease and stroke to diabetes, arthritis, multiple sclerosis, 18 forms of cancer including breast and ovarian, digestive disorders like Crohn's disease, even depression and chronic pain. Some studies suggest it protects against colds and flu.

Here's the lowdown on this wonder woman nutrient.

What D does It's a fat-soluble vitamin that helps the body absorb calcium and helps regulate the amount of calcium and phosphorous in the blood.

How much do I need? The magic number used to be 200 IUs a day, but most experts now recommend double that amount.

Do I have enough? A blood test will reveal your level; what's healthy varies depending on your gender and age.

How do I boost my D? Experts ascribe the current epidemic of D deficiency to sunscreen. Because we're vigilant about using sunscreen, we're not getting as much D from sunlight, a  major source. People with darker skin, which has more melanin, are at greater risk of running low on D. The solution: Eat foods rich in vitamin D, like salmon, tuna, or egg yolks, or foods that are fortified with D (milk, cereal, orange juice). Or choose a supplement. Most calcium supplements include vitamin D.