 Vitamin
A has the distinction of being the first fat-soluble vitamin to be
recognized. Today, after almost a century of research, Vitamin A and its
plant-derived cousin, beta-carotene, are still very much a focus of
research. Vitamin A is one of the most versatile vitamins, with roles in
such diverse functions as vision, immune defenses, maintenance of body
linings and skin, bone and body growth, normal cell development, and
reproduction. In addition to being crucial for eye health, Vitamin A is
needed by all epithelial tissue; that is the tissue which has an
external surface, and an internal lining; such as the nose, eyes, mouth,
genitalia, and so on. The skin and all of the protective linings of
these areas serve as barriers to infection by bacteria and to damage
from other sources. Vitamin A works at the genetic level to promote the
process of cell differentiation, which allows each type of cell to
mature so that it is capable of performing a particular function to help
bar infections from taking hold. Another emerging area of research
concerns the roles of Vitamin A in the regulation of the genes that
produce proteins involved in immunity. Without sufficient Vitamin A,
these complex genetic interactions produce an altered response to
infection that weakens the body's defenses against disease. Vitamin A
also assists in bone growth. Normal children's bones grow longer, and
the children grow taller, by remodeling each old bone into a new bigger
version. To do so, the body dismantles the old bone structures and
replaces them with new, larger bone parts. Growth cannot take place just
by adding on to the original small bone; Vitamin A is needed in the
crucial dismantling steps. In some children, failure to grow is one of
the first signs of Vitamin A deficiency |
Recommended
Dietary Allowances: Men = 5000 IU (or 3 mg beta carotene); Women = 4000 IU (or
2.4 mg beta carotene)
IMPORTANCE:
- Necessary for growth & repair of body tissues
- helps maintain smooth, soft disease-free skin
- helps protect the mucous membranes of the mouth, nose ,
throat & lungs, thereby reducing susceptibility to infections
- protects against air pollutants
- counteracts night-blindness & weak eyesight
- aids in bone and teeth formation.
- Current medical research shows that foods rich in Beta
Carotene will help reduce the risk of lung cancer & certain oral cancers.
- Unlike Vitamin A from fish liver oil, Beta Carotene is
non-toxic.
DEFICIENCY SYMPTOMS:
- May result in night blindness
- increased susceptibility to infections
- rough, dry, scaly skin
- loss of smell & appetite; frequents fatigue
- lack of tearing
- defective teeth & gums' retarded growth
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