Have you been taking yours vitamins?

The days of fruit flavored Fred Flinstone chewable tablets are over for most of us, but according to the National Research Council, which determines nutritional needs for the U.S. government, a healthy body still needs a daily supply of eleven essential vitamins and seven minerals

Vitamins, substances which are required in small amounts but cannot be synthesized by the body, play two basic roles Molecules derived from the water soluble vitamins such as vitamins B and C. help the body's enzymes complete a number of biochemical reactions Fat soluble vitamins A, D, E and K perform a variety of functions from forming the light-sensitive pigment of the eye vitamin A to maintaining healthy skin vitamin D.

The balance of research appears to support the idea that the right amount of vitamins and minerals contributes significantly to good health. According to the American Cancer Society, a balanced diet and sufficient intake of each vitamin and mineral can reduce the chances of illnesses such as cancer and heart disease.

Vitamin A and its altered form carotene have been shown to inhibit tumor formation in some animals.

"Beta-carotene, a precursor of Vitamin A, has been associated with a decrease in the chances of heart disease," says Lillian M. Sonnenberg, manager of Massachusetts General Hospital's Nutrition Service. "A lot of research is pointing to beta-carotene as having a clear relationship with the chances of cancer"

Susan Katz Cohen, spokesperson for the Massachusetts Dietetics Association, cites the advantages of Vitamin C. "Research points out that it can reduce the seventy of the cold," Katz-Cohen says. "Vitamin C and also Vitamin E can prevent oxidation of certain things like cell membranes, which makes you less prone to cellular damage that causes cancer."

Some vitamins are easy to come by. A single orange, for example, provides 116 percent of the U.S. Recommended Daily Allowance (RDA) of Vitamin C, which helps the body fight off colds and may lower the risk for cancer of the larynx, esophagus and lung.

In the cold weather, says CVS pharmacist Sara Zemui, consumer demand for a number of vitamins, including vitamin C, an antioxidant, increases. "More people are wanting to take Vitamin C because of the cold weather," Zemui says.

But other essentials may be more difficult to find in daily foods, especially for vegetarians or others with special diets, and nutrition experts are split on whether people should take regular vitamin or mineral supplements.

Most specialists agree that if possible, people should be concerned with getting most of their requirements in their daily food intake. According to Sonnenberg, nutritionists' focus has been redirected to the relative importance of food groups.

"The key is to eat a variety of food, especially orange fruit and green vegetables that are nutrient dense," Sonnenberg says. "Nowadays, there is more emphasis on eating fruit and vegetables during meals."

To better incorporate these nutrients into food groups, the Department of Agriculture last year established a food guide pyramid, organized by food groups in the order of frequency they should be eaten.

"We've gone from four food groups to five food groups," Sonnenberg says. "The design of the pyramid is that the foundation of the food groups, bread, fruit, and vegetable is where you should focus your diet on."

For Harvard students, whose diet consists mainly of Dining Services fare and the occasional pizza, the challenge of meeting nutrition needs is left to director Michael P. Berry.