Table of Contents
With all the vitamin buzzword hype going around these days, we don’t hear a whole lot about vitamin A.
Most health enthusiasts can talk for hours about next big antioxidant or Omega-3s, but vitamin A rarely seems to come up.
I guess you could say vitamin A is like that hard working but under-appreciated office worker who keeps everything running smoothly but never gets the acknowledgement he deserves.
So What Does Vitamin A Do?
Vitamin A best known for its role in supporting visual function.
It’s needed by the retina for both low-light and full-color vision.
One study found that when a mother pig was deprived of vitamin A, she gave birth to a litter of piglets without retinas.
This may be because the mother’s own lack of vitamin A prevented development of retinal tissue in the litter, or possibly because a lack of vitamin A suggests a lack of light, making vision useless.
This may explain why some cave-dwelling creatures seem to have the potential for eyesight but are born blind.
Vitamin A is also responsible for proper hormone function, the details of which are beyond the scope of this article.
Types of Vitamin A
The two main types of vitamin A are retinol and the carotenes (beta-carotene, gamma-carotene, etc).
Retinol is mostly found in animal food sources and carotenes are mostly found in plant sources.
Omnivores and herbivores have the capacity to convert carotenes into retinal, the usable form of vitamin A, but carnivores do not.
Vitamin A Deficiency
Given the relatively low level of awareness of importance of vitamin A, the effects of deficiency on a global scale are no less than shocking.
It is estimated that nearly a third of children under 5 suffer from vitamin A deficiency (most of them in developing countries) resulting in 2/3 of a million deaths each year, according to a 2008 study of undernutrition.
Increased awareness and access to vitamin A has been voted one of the best investments for global welfare and development.
In the US, vitamin A deficiency is a smaller but still under-represented issue.
Sources of Vitamin A
- Sweet Potatoes
As we can see from the global epidemic in developing countries, vitamin A is incredibly important, especially for children.
Eating a healthy diet and balanced diet is a good idea, but under circumstances where that isn’t possible, supplementation is necessary.
Side effects tend to occur at levels above 25,000 IU per day in adults, but some negative effects have been found at 15,000 IU per day.
Children can reach toxic levels if taking more than 1500 IU per kg of body weight, or about 700 IU per pound.
READ : What vegan foods have b12