Vitamin A

Considered essential for life, Vitamin A is available in a wide range of foods of both animal and plant origin, and you can find it easily in common foods.

I’ve found Vitamin A in natural animal sources such as beef, beef, pork, chicken, turkey and fish liver, eggs, butter, whole milk, mozzarella and cheddar cheese and use several sources routinely. Egg substitutes are also on this list.

Plant sources are not always standard daily fare, but do offer a variety of fruits and vegetables for a change of pace.

Plant sources include:

* sweet potatoes
* carrots
* beetroot
* broccoli
* spinach
* winter squash
* kale
* peas
* sweet red peppers
* oatmeal
* tomato juice
* apricots, fresh and dried
* peaches
* apples
* lemons

from doctoryourself.com:

Vitamin A as CAROTENE:
Chronic fatigue syndrome encompasses a depressed immune function. Your immune system is stronger when beta-carotene is adequately supplied by the diet. And, not at all surprisingly, vitamin A deficiency weakens immune function. (Chandra, R. K. "Nutrition and Immunity: Basic Considerations, Part 1," Contemporary Nutrition, Vol 11, No. 11, 1986) "Fewer than 10% of us actually consume "adequate" beta-carotene." (Patterson, B. H. et al, "Fruit and Vegetables in the American Diet: Data from the NHANES II Survey," American Journal of Public Health, 1990, 80:1443-1449). This means that supplements are virtually essential.

For example: after surgery, the body's inventory of lymphocytes does NOT decrease (as it otherwise will) when large doses of vitamin A are given. (Cohen, B. et al: Reversal of Postoperative Immunosuppression in Man by Vitamin A," Surgery, Gynecology and Obstetrics, 149:658-662, 1979.)

Beta-carotene supplements in particular have been shown to strengthen the immune system by helping the body to build more helper T cells. (Alexander, M et al: "Oral Beta-carotene Can Increase the Number of OKT4 Cells in Human Blood," Immunology Letters, 9:221-224, 1985.) The amount used in this well-controlled study was 180 milligrams of beta-carotene per day. This is, theoretically at least, the equivalent of 300,000 I.U. of vitamin A per day! Even AIDS patients have benefited from dosages such as this (Graham, N. American Journal of Epidemiology, December, 1993). Surely AIDS is the ultimate immune dysfunction.

The body (ideally) can derive 10,000 I.U. of vitamin A activity from each 6 milligrams of beta-carotene consumed. The actual yield is almost certainly lower, however. Studies using small amounts of beta carotene (20 mg or so) are likely to show no benefit even though the "theoretical" yield would be over 30,000 I.U. of Vitamin A activity. 30,000 I.U. is six times the US RDA for vitamin A. Either that isn't enough, or beta-carotene isn't converted nearly as efficiently as supposed. Or both.

The safest way to give Vitamin A is as beta-carotene, as the body will convert it into vitamin A as needed and overdose is automatically avoided. Excessively large does of preformed, fish oil vitamin A may actually depress immune function; huge doses of beta-carotene do not appear to have that negative effect.