by Darcia Helle

Created on: April 18, 2009

Vitamin A is vital for a variety of bodily functions. These include:

Maintaining healthy teeth.

Building strong bones.

Strengthening the optical system.

Growth and maintenance of healthy skin and tissue.

Protection from cardiovascular disease and cancer.

Promoting good vision, particularly in low light.

Reproduction and breastfeeding.

Cell division and cell differentiation (a process in which a cell becomes part of the brain, muscle, lungs, blood, etc.).

Regulation of the immune system.

Vitamin A occurs in 2 forms: preformed vitamin A, also known as active vitamin A, and provitamin A.

Preformed vitamin A is better known as retinol. This is considered the active form because it most immediately usable form. Retinol is fat-soluble, meaning it is stored in the liver and requires dietary fats for absorption. Large amounts of this form can be toxic, as the body does not rid itself of the excess.

Retinol is found only in animal foods. Sources that are especially rich in retinol are fish liver oils from cod, halibut, salmon, and shark. Other good sources include eggs and dairy products.

Provitamin A is actually a group of carotenoids. Carotenoids are dark colored dyes found in plant foods that the body turns into vitamin A as needed. Scientists have identified 563 carotenoids. Few of these can be used by the body to produce vitamin A. The best known and researched carotenoid as a vitamin A precursor is beta-carotene.

Beta-carotene is an antioxidant, which functions to protect cells from damage caused by free radicals. Free radicals are unstable by-products of oxygen metabolism that contribute to illness and the degenerative process of aging.

Beta-carotene is considered non-toxic. The body will only convert this to vitamin A when needed. Excessive beta-carotene intake can result in a yellow / orange cast to the skin, which is sometimes seen in those who drink extreme amounts of carrot juice. This condition is harmless and will correct itself as soon as the beta-carotene intake is lowered.

Beta-carotene is only found in plant-based foods. Sources include carrots, pumpkin, sweet potatoes, winter squash, cantaloupe, broccoli, kale, and spinach. As a general rule, the more intense the color of the fruit of vegetable, the higher the beta-carotene content will be.

Many healthcare practitioners find that beta-carotene works remarkably well in the treatment of acne, as well as eczema and psoriasis. Beta-carotene is completely nontoxic, allowing high doses to be used safely.

Human

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