DEAR readers, if you think that is all that vitamin A does, then you are in for a big surprise. Understandably, vitamin A has been instilled in our minds- elementary, secondary, college- about the role of vitamin A and the eyes, in almost the same relationship as a horse and its carriage.
A big surprise, especially for those who are very conscious and concerned about their physical looks, vitamin A joins vitamin C and vitamin E as anti-oxidants, therefore it helps a lot in delaying the ageing process.
As an oxidant, vitamin A helps in preventing harmful oxygen radicals- oxygen species with odd number of electrons in their outer orbitals, examples of which are oxides of carbon from automobiles and coal-fired factories- harm and eventually destroy the cells of the body, thus, if the location is the face, there would be dry, sagging skin and wrinkles.
Vitamin A, together with vitamin C, are the ones which establish a very solid, sturdy and and durable foundation- osseous matrix for bones, chondroid matrix for cartilage, dentoid matrix for teeth- which are later further deposited on with calcium and phosphorus, so that these structures will be healthy and functioning well even in our adult life.
Well, as for the eyes, once and for all, it is time to put everything in their proper perspective. The sad reality is, when our teachers tried their best to encourage us to eat kalabasa or squash because of its rich vitamin A content with the hashtags- a word non-existent then, “for beautiful eyes”- it has nothing to do with extending the length of your eyelashes, or the iris whose pigments determine the color of your eyes or the graceful arching of your eyebrows. In other words, vitamin A has none of the so-called cosmetic effects or beautifying effects of one’s eyes.
Putting it simply, vitamin A makes us see things clearly, that is if we have normal 20/20 vision. Vitamin a is an important component of the so-called visual pigments, rhodopsin which our eyes use when we are in a pitch dark room, we are able somehow to distinguish figures from shadows; iodopsin or visual violet when we see things in an illuminated room or appreciate the colors of the rainbow.
H, unlike the term “nyctalopiaowever at this juncture, allow me to digress momentarily, if just to stress that color blindness is a total different entity, not at all related to a deficiency of vitamin A unlike the term “nyctalopia” or night blindness (arrap in Ilokano) which is a very common symptom, or keratomalacia- roughness and eventual ulceration of the cornea.
The recommended daily dose of vitamin A is from 3000 to 4500 I.U. (international units) with the higher dose prescribed for pregnant women.