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.

Currently meal plans do not take vitamin and mineral content into account, Berry says, but the future will include more nutritional analysis.

"Looking at what students want to eat is certainly our number one priority," Berry says. "Right now, we don't sit down and analyze the nutritional content of the food."

Dining Services recently purchased the Computrition software program, which traces more than 100 nutrients, including elements in minute amounts, in foods. As a part of the effort for increasing food quality, 10 cooks are currently attending a culinary school, and during spring break the crew will gather to focus on quality, including nutrition, Berry says.

"We want to define what light and healthy mean to the students and what they want," Berry says. "We want to enhance the menu and redirect our menu management."

Those students who suspect their usual diet of chickwiches and french fries may be low in certain nutrients can find vitamins and minerals in the form of pill supplements on store shelves But Sonnenberg emphasizes the diet as the main supplier

"As we continue to learn about the diet, there is more we've been finding out about what the food can do for our bodies that vitamin and mineral supplements can't, Sonnenberg says

Sonnenberg recommends a daily multivitamin only for backup purposes, not to exceed the RDA. "If people want to take vitamin and mineral supplements as backup. I would recommend one that provides up to 100% of U.S. recommended daily allowance," Sonnenberg says.

According to Diane Bleday, a nutritionist Clinic Medical Center in Burlington, vitamin deficiency is very rare in the United States "because there are so many varieties of food."

Walter C. Willett, chair of the Harvard School of Public Health's Department of Nutrition, disagrees. focusing on an increasing portion of the population that may be lacking certain vitamins and minerals.

"It's probably more common than we thought," Willett says. "Birth defects suggest that there is a substantial number of women who don't get enough folic acid."

Whatever the prevalence of nutrient deficiency Johanna T. Dwyer, director of the Frances Stern Nutrition Center at New England Medical Center Hospital, stands firmly against consuming supplements.

"If you eat according to the recommended allowance, you can get all the nutrients you need," Dwyer says. "Sometimes people tend to think that if they take the supplements, they don't have to eat the food."

The only exceptions, Dwyer says, should be strict vegetarians, who can benefit from iron supplements. Dwyer also recommends specific vitamin and mineral supplements to compensate for those that individuals lack, rather than a multivitamin.

"It used to be that nutritionists though people were getting enough nutrition from food, but I think a number of people are starting to rethink that," he says. "There probably is a large number of people who are not getting the optimal amount and we are finding ourselves broadening the number of people whom we think might benefit from a daily multivitamin."

women, says Katz-Cohen, can especially derive advantages from supplements of iron, which is important for the formation of the blood's oxygen-carrying molecule, hemoglobin.

"Some minerals like iron and calcium affect women more than men." Katz-Cohern says. "Menstruating women should stick to a multivitamin that contains iron."

While supplements can benefit, the "mega-dose," taking too much of a given nutrient, can be harmful, says Bleday. The mega-dose usually consists of 10 times the RDA.

"The ones we are concerned about are the fat-soluble vitamins like Vitamin A and D that are stored in the fat cells," Bleday says. "When vitamins and minerals are taken in very large doses, they can only be considered medication."

A large buildup of fat-soluble vitamins, which are poorly excreted by the kidneys, can produce toxic effects. According to Willett, vitamin D can cause seizuers and death if taken in extreme excess, and vitamin A and cause liver problems.

The American Cancer Society additionally warns that too much vitamin A and D may cause headaches, blurred vision, injury to the nervous system, and other effects. Recent research has shown toxic levels of vitamins to be connected with both fat soluble and water soluble vitamin.

Willett admits that the debate over the right diet still rages. But he says that the ambiguities may soon be resolved, as researchers continue to investigate the effect of vitamins and minerals.

"There are going to be a few major papers published in the next several months that will help us understand vitamins and minerals," he says