Retinoids vs. Carotenoids

The most important fact about vitamin A is the difference between retinoids and cartenoids. The vitamin A from animal sources is retinoids, also called retinol, while plant source vitamin A is carotenoids, such as beta carotene.

Animal sources of retinol is bio-available, which means the body can utilize it. The vitamin A from plant sources, in contrast, must first be converted to retinol to be useful in the body. This poses two big problems.

First, when we are in pristine health, it requires at least six units of carotenes to convert into 1 unit of retinol (source). To put this in perspective, that means one must eat 4 1/2 pounds of carrots to potentially get the amount of useable A as in 3 oz. of beef liver (source). What happens if we have digestive issues, hormone imbalances, or other health problems? It requires even more units of carotene in the ratio.

Second, the carotene-to-retinol conversion is HIGHLY compromised. As a matter of fact, this conversion is negligible for many individuals. This conversion is virtually insignificant:

In infants
In those with poor thyroid function (hypothyroidism)
In those with diabetes
In those who are on a low fat diet or have a history of low fat dieting
In those who have compromised bile production

As with other orange veggies, sweet potatoes provide carotenes. Although beta carotene is an antioxidant, it is not true vitamin A. We must eat true vitamin A foods on a daily basis to meet our requirements for this essential nutritient.

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