By: Dr. John Bagnulo, Director of Nutrition
When we speak to healthcare providers and consumers about the vitamin A levels in Liquid Hope and Nourish, they sometimes state their concern regarding the high levels present in the formula. But when we take a look at physiology, nutrient conversion, and the differences between animal (active) and plant (provitamin) forms of vitamin A, we realize that there isn’t anything to be concerned about.
Fully formed and biologically active Vitamin A is known as retinol or retinyl ester. It is measured in both micrograms and International Units (IUs). The RDA for adults ranges from 700 to 900 micrograms (1mcg =3.33 IUs) or approximately 3000 IUs. The tolerable upper level (TUL) of the safe range is 10,000 IUs for pregnant women and all adults. The body converts different carotenoids to vitamin A (retinol/retinyl esters) at varying rates. This conversion is a function of the type of carotenoid consumed (beta carotene, alpha carotene, lycopene, lutein, etc.), the individual’s nutritional status, and the individual’s genetics. There is wide variability based upon the fruit or vegetable source and an individual’s genetic expression for conversion. In general, it takes approximately 18,000 to 36,000 IUs of mixed carotenoids to generate 3000 IUs of vitamin A in the form of retinol.
Carotenoid consumption has never been shown to generate vitamin A toxicity. This is a function of a biological feedback loop where less is converted with higher levels of circulating vitamin A. Additionally, and equally important, carotenoids are converted to vitamin A at low rates and at a much slower speed. Some carotenoids that are not converted may end up being stored in fat cells and can, at very high levels of consumption, generate a slight change in an individual’s skin color. This increase in stored carotenoids is known as hypercarotenoidosis and is associated with a reduced risk of several forms of cancer.
The amount of carotenoids in Liquid Hope and Nourish are not capable of generating any type of vitamin A toxicity. They are present at moderate levels and are from the sweet potato, carrot, and green vegetable content found in the formulas.
Dr. John Bagnulo is the Director of Nutrition at Functional Formularies and leads nutrition research and development initiatives. Learn more about Dr. Bagnulo here.