Vitamin A, C and Folacin in The Mediterranean Diet

Vitamins are chemical substances in vegetables (and other foods) that have a variety of jobs in the body, from as­sisting the chemical reactions that make your body function to promoting growth to preventing infection. There are two kinds of vitamins: water soluble and fat soluble.

Water-soluble vitamins dissolve in water and move through your bloodstream quickly. These vitamins, which include thiamin, riboflavin, niacin, vitamin B6, folacin, vita­min B12, biotin, pantothenic acid, and vitamin C, must be in­gested regularly because the body doesn’t store them. Among the many life-supporting functions of water-soluble vitamins, folacin and vitamin C have been shown to have anticancer functions, especially when paired with the fat-soluble vitamin E and beta-carotene (a form of vitamin A).

The fat-soluble vitamins—A, D, E, and K—dissolve in fat and are stored in your body for longer periods of time. (For example, the body is capable of storing up to a year’s supply of vitamin A.) Beta-carotene (a form of vitamin A found in vegetables) and vitamin E have been given a lot of attention lately as powerful antioxidants (more on antioxi-dants later). Many studies have linked these nutrients with the prevention of certain chronic diseases such as cancer and heart disease. Although the major food sources of vitamin E are nuts (especially the almond), seeds (especially sunflower seeds), wheat germ, and certain oils, there are a few vegetables that also contain appreciable amounts of vitamin E, most notably the sweet potato and avocado. Because many vegetables contain vitamin A, we will highlight this powerful nutrient (along with the other cancer-fighting vitamins, C and folacin) below.

In keeping with the spirit of the traditional Mediterranean diet, we recommend getting your vitamins from vegetables (and the other foods listed in the daily and weekly sections of the Mediterranean Diet Pyramid) rather than from supplements. Unheard-of in traditional Mediterranean culture, supplements would have been unnecessary anyway, given the nutrient density of the diet. We suggest getting your vitamins and other nutrients the way nature intended!

Famous for promoting good vision, this fat-soluble vita-min facilitates a number of other important bodily pro-cesses. Vitamin A plays a vital role in maintaining healthy skin and healthy tissues found in your mouth, genitals, and digestive and urinary tracts. It also assists with the proper development of fetuses, sperm production, growth of chil-dren, and more. In terms of cancer prevention, vitamin A’s importance in supporting the immune system makes this nu-trient a powerful ally in the fight against cancer.

Getting adequate amounts of vitamin A is easy in a vegetable-rich Mediterranean diet. Identify vegetable sources containing vitamin A by their orange color, and you’ve got beta-carotene—a substance that converts to vita­min A in the body. Beta-carotene, a phytochemical that we’ll discuss below, is also a potent antioxidant. Sweet po­tatoes, carrots, and melons—staples in the traditional Mediterranean diet—contain lots of beta-carotene. Pump­kin, native to North America, also contains high levels of beta-carotene and can easily be included in a Mediterranean diet, especially when you grow it yourself or buy organic pumpkins from local growers.

Vitamin C, also called ascorbic acid, first gained fame when nutritionists discovered it warded off scurvy in sailors. Scurvy, a condition characterized by swollen, bleeding gums and tooth loss, rarely occurs today, and typically signifies malnutrition. Vitamin C’s next claim to fame has been its ap­parent ability to fight off the common cold. Because of this potential cold-busting capacity, many Americans customar­ily load up on vitamin C supplements, but nutrition scientists still aren’t sure how much vitamin C may actually help ward off the common cold. What scientists do know is that taking large doses of this vitamin can lead to more serious prob­lems, such as the formation of kidney stones and diarrhea. Vitamin C also helps the body absorb the iron found in plant foods. So, the vitamin C–rich Mediterranean diet helps to en­sure adequate iron absorption for the average adult.

Recently, this vitamin has become associated with chronic disease prevention, namely heart disease and cancer. Vitamin C’s antioxidant abilities and its important role in maintaining a strong immune system is one reason, but its other role of collagen production makes vitamin C all the more beneficial in cancer prevention. Collagen is a protein-based substance that acts as structural material in skin, mus­cle, lung, and bone. The stronger this structural material, from a diet rich in vitamin C, the less likely cancer will invade these tissues. The presence of vitamin C in the diges­tive tract has been shown to prevent the formation of ni­trosamines, those believed cancer-causing substances found in cured meats. Vitamin C also works hand in hand with vi­tamin E to deactivate cancer-promoting free radicals.

In addition to cancer prevention, vitamin C helps to pro­mote a healthy heart. There is even some evidence that in­creased intake of vitamin C may help to improve one’s blood cholesterol profile by lowering the level of “bad” LDLs and raising the level of “good” HDLs.

The recommended daily allowance (RDA) of vitamin C for the average adult is 60 milligrams. Pregnant women need 70 milligrams, and breastfeeding moms need about 90 to 95 milligrams per day. Many researchers feel that more than this is needed to prevent disease, although just how much is still unknown. Smokers do need to get more than the standard RDA, about 100 milligrams daily, because smoking can deplete the body of this nutrient. Getting ade­quate amounts of vitamin C can easily be accomplished in a varied Mediterranean-type diet rich in fruits and vegetables. Eat just one orange, and you’ve already consumed 60 mil­ligrams of vitamin C. Many vegetables are also rich sources of vitamin C. Those most relevant to the traditional cuisine of the Mediterranean include tomatoes, green and red pep­pers, broccoli, spinach, potatoes, and asparagus.

The word folacin is from the Latin word folium, or “fo­liage,” because folic acid was first discovered in leafy green vegetables. Also known as folate or folic acid, this water-soluble B vitamin is essential for several important func­tions in the body. For one, it is crucial in the synthesis of DNA, and because of this, any body tissue that is dividing and growing needs ample amounts of folacin. Cells lining our digestive tract are continually regenerating themselves and therefore rely on folacin to do so. Pregnant women need substantial amounts of folate (more than twice the RDA for the average adult) to support the growing fetus.

The U.S. Public Health Service recommends that all women of child­bearing age eat 400 micrograms of folacin daily to ensure adequate stores of folacin to support the large demands of this nutrient in pregnancy. Women who enter into pregnancy without adequate folacin stores and/or those who do not eat enough folacin during pregnancy (particularly in the first trimester) run the risk of bearing a baby with inadequate brain and spinal cord development.

Folacin’s supporting role in DNA synthesis appears to make this nutrient important in the battle against cancer, particularly cancer of the colon. Reports in the Journal of the National Cancer Institute showed that a high folate in­take lowered colon cancer risk. Some researchers feel that intakes of 400 to 800 micrograms of folacin are needed for cancer prevention, but this is still being determined. The Mediterranean diet provides ample amounts of folacin, es­pecially with its emphasis on bean and vegetable consump­tion (see the following Questions and Answers section). The vegetables richest in folacin include avocados, artichokes, asparagus, spinach, mustard spinach (tendergreen), and turnip greens.