Vitamin A versus carotenoids
True vitamin A occurs only in animal foods. Compounds called carotenoids, which are found in plant foods, are precursors to vitamin A and can be converted into vitamin A. (You may be familiar with beta-carotene, a carotenoid compound responsible for the orange and green pigments in foods such as carrots, sweet potatoes, cantaloupe, and various leafy greens. Other carotenoids you might be familiar with, such as lutein and lycopene, do not have vitamin A activity.) Carotenoids are not a dependable source of vitamin A for all individuals because absorption of carotenoids from plant foods varies widely and is influenced by numerous factors. These include processing techniques, the concentration of the carotenoid in the food, and the amounts of dietary fat, fiber, and preformed vitamin A in the diet, as well as an individual’s vitamin A status and gut integrity. Genetic factors also affect carotenoid metabolism, with some people’s bodies converting carotenes into vitamin A more readily than others’. Regarding preformed vitamin A, various health conditions and use of certain pharmaceutical drugs may reduce absorption, so some individuals may benefit from supplementation.
Vitamin A plays a critical role in supporting immune function. Several different types of cells with distinct functions all contribute to a healthy immune system. Vitamin A influences the differentiation and specialization of these cells so that they can perform their unique roles. This key nutrient also contributes to the structural integrity and barrier function of the skin and the lining of the intestines and respiratory tract, which are among the body’s first lines of defense against unwanted organisms.*
Other roles of vitamin A
Apart from supporting immune function, vitamin A is well known for promoting eye health-specifically, it is required for helping the eyes adjust to different levels of light or darkness and also plays a role in helping to distinguish different colors.* Vitamin A is needed for healthy thyroid function and production of thyroid hormones, as well as for supporting mobilization of iron from body stores so it can be incorporated into red blood cells.* Vitamin A’s influence on thyroid hormones and red blood cells means it may also contribute to cellular energy production (which influences overall energy levels), a healthy metabolism, and a positive mental outlook.
Always be sure to speak with your healthcare provider before starting any new nutritional supplement when pregnant or nursing. For children, we recommend speaking with your child's pediatrician regarding proper dosing. Store away from children.