Vitamin C: how much do you need?

Natural Health, Sept-Oct, 1998

Some experts think You'd have to eat a Hundred-pound orange To get what you need. Is it possible to get it From food? Is it safe To get it from a pill?

Natural Health recently surveyed people's vitamin C-taking habits. Four of those who answered said: "I take a gram a day. I'm not sure it's doing anything, but I feel it's helping to prevent heart disease." "Never taken it. Never will." "It's a waste to take more than 200 milligrams." "There's no maximum level for vitamin C."

What's surprising about these answers is they all came from doctors. Not ordinary doctors, but ones who are "up" on the latest nutritional science.

It shouldn't surprise anyone then that nonscientists also were all over the map when it comes to C.

Beyond our informal survey, we know that millions of Americans swallow a one-a-day drugstore pill that contains the Recommended Dietary Allowance (RDA) of 60 milligrams of C. And millions of others take no vitamin C at all, including 20 percent of Natural Health employees (although two-thirds of them do use it when they're sick or stressed).

Of course, there are people like the late two-time Nobel prize winner Linus Pauling, Ph.D., who told Natural Health a year before he died that he took 18 grams a day--more if he got sick. Pauling's skin looked rosy and his eyes sparkled during that meeting, and he still, at age 92, worked a full day. Or there is one of Pauling's proteges, physician Robert F. Cathcart III, M.D., of San Mateo, Calif., who told us he gives 200 grams a day intravenously to patients with serious infectious illness, such as hepatitis or AIDS.

The reason people take vitamin C at all is that thousands of studies over the past three decades have provided durable evidence that it prevents and helps cure a lot of illness and disease--from bed sores to cancer. Despite the research, troubling questions remain, starting with how much, if any, a person should supplement to receive benefits. Some people appear to be healthy while getting their C strictly from their diet. Others amazingly don't even bother to figure in their intake from food. They think to get the C you really need, you just take a supplement.

And now we have the recent findings of British researchers who reported in the April 9th issue of Nature that a mere 500 milligrams daily of supplemental vitamin C taken for six weeks can cause genetic damage.

Can sense be made of all this? Following are answers to eight questions that just might clear up the confusion.

Why do I need vitamin C in the first place?

For starters, you would die without any at all. At least 300 functions in the human body depend on adequate levels of vitamin C, starting with the manufacture of collagen, a protein substance found in skin, ligaments, bones, and many other body tissues. Collagen acts as a cementing substance between cells, forming a protective barrier against infection and disease and promoting healing of wounds, fractures, and bruises. Among ascorbic acid's (the chemical name for C) other 299 known functions are the formation of red blood cells and maintenance of strong blood capillaries; assistance in the absorption of other nutrients, such as iron; production of antibodies and maintenance of white blood cell function and activity (which may give C its cold-fighting ability); keeping the central nervous system and brain working at optimal levels (in one study, a group of geriatric patients who experienced confusion and had low levels of vitamin C showed dramatic improvement when given C); and antioxidant protection against free radical compounds that initiate disease and the aging process.

Is it possible to get enough C from my diet?

It depends on what you mean by "enough C." If it's 10 grams a day, which some hard-liners insist upon, then, no, you'll have trouble getting that from food without becoming ill. You'd have to drink 88 eight-ounce glasses of fresh orange juice, or munch on 53 three-and-one-half-ounce servings of raw red peppers.

But if you think enough C is 60 milligrams (the RDA), then food will easily do the job. To get this amount, the recommended standard for decades, you only need to eat 3 ounces of cooked broccoli. (The RDA for pregnant females is 70 milligrams and, for lactating females, 95 milligrams.) Yet few experts today consider 60 milligrams enough; it was originally set to prevent scurvy Allison Yates, director of the Food and Nutrition Board of the National Academy of Sciences, which sets RDAs, says the academy is "rethinking" the RDA for vitamin C, along with other nutrients, taking into consideration new evidence about supplements and chronic disease.

Nor is it difficult to get the 250 milligrams that a number of scientists now think is ideal: Eat one orange (53 milligrams), a kiwi (98 milligrams), one 3.5-ounce serving of cooked broccoli (75 milligrams), and one 3.5-ounce serving of cooked cauliflower (31 milligrams). If you want 500 milligrams, just add a 9-ounce glass of fresh orange juice (130 milligrams) and a 3.5-ounce serving of raw red peppers (190 milligrams).