Vitamin A, Beta-Carotene And Their Safety

Friday, July 30, 2010

 

Although Vitamin A deficiency is prevalent throughout the world, retinol toxicity is a common occurrence as well. About 5% of those who supplement with vitamin A unknowingly suffer from toxicity symptoms. It should be noted that supplementation at 5,000 - 10,000 IU per day of preformed vitamin A, which is dose that is well within the range that is offered in many popular vitamin supplements is a safe effective doses, additional supplementation of vitamin A may actually lead to a cumulative toxic overdose. Additionally, accidental ingestion of one single, large dose of vitamin A, can produce acute toxicity in children, always keep vitamin A out of reach of small ones.

A large study on over 22,000 pregnant women who supplemented with vitamin A during early pregnancy found that those women taking more than 60,000 IU of preformed vitamin A per day in the form of supplements had about one in fifty-seven of a chance of a malformation attributable to the supplement. In consuming more than 60,000 IU of vitamin A, a five-fold greater risk for birth defects arises as compared to consumption of less than 25,000 IU per day. The prevalence of birth defects seems to be greatest in those women who consume high levels of pre-formed vitamin within the first seven weeks of their pregnancy. Authors of the study concluded that women who may possibly become pregnant should limit their retinol intake to below 15,000 IU, or supplement with beta-carotene instead.

Beta-carotene is the orange/yellow-colored pigment that is often found in many garden vegetables. It is a retinal precursor. The body is able to easily convert beta-carotene into vitamin A by turning the carotene molecule into two molecules of retinol as they are needed. This allows for the avoidance of toxic accumulation of pre-formed vitamin A. Once beta-carotene is transformed into active retinol, it offers the same beneficial affects. The only symptoms associated with beta-carotene supplementation are loose stools or slight discoloration of the skin. This makes beta-carotene, even at high doses, safe for the body because it does not exhibit toxicity. An added benefit of beta-carotene is that it is a much more potent antioxidant than retinol, as it provides even greater protection against oxidative challenges. The worst thing that can happen to you if you take too much beta-carotene is that you may turn orange like a carrot. However, this should not be a worry because you will be just fine.

The majority of nutrients that are used in supplementation have a large measure of safety. Unfortunately, the use of vitamin A warrants prudence and caution. This is especially crucial when it is consumed by children or those women who are pregnant. Because of this, the level of vitamin A in excess of the upper limit of intake that is prescribed by the Food and Nutrition Board of the Institute of Medicine, is a crucial criterion in determining how good a product is. The criterion for potential toxicities asks whether the nutritional supplement contains vitamin A. If so, it asks whether the potency of vitamin A exceeds 100% of the upper limit of intake that is prescribed by the US Food and Nutrition Board.

To be on the safe side, take beta-carotene which has no side effects even at very high doses but exhibits the same health benefits of consuming preformed vitamin A. Look to your local or internet vitamin store for name brands like Solaray and Source Naturals for all your Vitamin A and beta-carotene needs.


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