Vitamin A & Bodybuilding

By Grant Henderson

In spite of the great amount of information available on the values and benefits of vitamins, many people are dismissive of them if not completely unaware. While bodybuilders, being athletes who place great importance on nutrition and health, tend to include vitamins in their dietary plans, most ignore the fact that vitamin A can be a very positive nutrient for muscle building.

It still surprises that even younger bodybuilders, who in all likelihood have some kind of tertiary education and would thus be well-informed, largely ignore vitamin supplements while literally throwing money at all manner of exotic products that promise to gain them strength, size, power, etc. This is a serious mistake, since vitamins and minerals are not only amongst the cheapest supplements around but also, in my humble opinion, the most effective.
Of course, vitamins do not contribute directly to muscle growth, but they are essential to many organic processes that improve internal function of the body, which consequently allows better performance in the gym and increased capacity for recovery, leading indirectly to greater physical development.
This is the case with vitamin A, which people tend to associate only with eyesight but is actually essential to the human body and can have positive effects on physical performance and development. 

Vitamin A Exposed
From time immemorial liver was used as a cure for night blindness, characterised by poor eyesight at night or in conditions of low light, but it was only at the beginning of the 20^th century that scientists understood that the organ was one of the best-known sources of vitamin A, a substance essential to good eye health.
As vitamins were discovered they were named according to the letters of the alphabet, as such vitamin A was the first. In 1913 two American scientists found in butter and egg yolks a substance necessary to growth in rats. It was the first known vitamin and, having been found in fat, was called “liposoluble vitamin A”. The complete structure of vitamin A was not identified until 1930, and five years later it was discovered to be essential to correct vision. In the years following studies confirmed its actions within the body and its vital roles in growth, development and reproduction.
In fact there are various substances that fall into the group known as vitamin A, meaning they all perform the same functions within the body. One of these is retinol, deriving its name from the retina, and it is used to make comparative measures of the other similar compounds.
Although the vitamin A we get from food exists in different forms, they can be classified under two types: preformed and pro-vitamin. The first is found in animal sources, like liver, butter, milk and egg yolk, and is utilized directly in the body as it has been preformed by another organism. The second type is found in vegetable sources and has to be converted by the body before use. Of the latter there are around 50 varieties that fall into the generic group of carotenoids, the most well known being betacarotene.
In all forms, both preformed and pro-vitamin, vitamin A is liposoluble, which means it is stored in fat in the human body. 

Effects Within The Body
Believe it or not, vitamin A is directly or indirectly involved in the function of practically all organs in the body. Despite being the first chemically identified vitamin, its functions at a cellular level are not all known due to the extent of them and their complexity, but many of it actions are. For example, it is necessary for good eyesight, as it is involved in the production of substances that assist vision in low light.
Vitamin A is also necessary for the growth and repair of many cells, from those in bones and teeth to collagen and cartilage. We also know it is vital to cellular differentiation, in which non-specialised cells are modified to perform certain functions. So vitamin A plays a significant role in the development and maintenance of all kinds of tissue.
Epithelial cells cover the internal and external surfaces of the body and are found in the skin, lungs, inner ear, nose, gums, sex organs, glandular ducts and the cornea. Many of these cells produce mucous, which is necessary to lubricate certain tissues and protect them from invasive microorganisms, including the stomach and throat and the vagina and uterus. Vitamin A is indispensable to the formation of epithelial cells, and thus promotes the production of mucous.
Owing to its role in the development and differentiation of cells, vitamin A is of great importance during pregnancy, when it is involved in significant changes in cells and tissues.
The vitamin is also known for its anti-infection properties. In addition to its role in epithelial cell health, it also stimulates the immune system and various defensive white blood cells, thus reinforcing the body’s protection against infection.
Many studies have also claimed that it performs significant antioxidant activity against free radicals. 

Absorption & Storage
For the proper absorption of vitamin A the presence of fat and bile is required in the intestine. Healthy people will absorb up to 80-90% of vitamin A in the diet, as it combines with fatty acids in the intestinal wall to travel to the liver where 90% of the body’s vitamin A is stored and releases as necessary. 

Vitamin A Deficiency
In developed countries vitamin A deficiency is uncommon and tends only to affect those suffering liver problems or alcoholism. One of the first noticeable symptoms is night blindness, or difficulty seeing in low light, and in extreme cases a condition known as exophthalmia can occur, characterised by dryness in the eyes, corneal ulceration and puffy eyelids.
Dry skin is another sign of deficiency; as is stunted growth in children, weight loss, congenital malformation, poor hearing, swollen joints, testicular inactivity and low sperm count. Malformed teeth in children is also related to a lack of vitamin A.
Frequent throat or respiratory tract infection is closely linked to vitamin A deficiency, and is the result of a weak immune system. Some studies also suggest a relationship between vitamin A consumption and protection from various types of cancer, particularly in the lungs, breasts, head and neck.

Tolerance & Toxicity
As a fat-soluble substance vitamin A can be stored in the liver for extended periods, which means there is the possibility of intoxication by overdose. The first symptoms of overdose are headaches, chapped lips, dry skin, fatigue and mood swings, and skeletal pain and aching joints are also signs of an excess. In acute cases hair loss, dizziness, sight problems, vomiting, liver damage and a disrupted menstrual cycle may occur.
Very extreme cases of severe poisoning due to vitamin A overdose can lead to death, although there are very few cases on record. One of he most notable was that where Arctic explorers were forced to eat the livers of their huskies, which contained an extremely high concentration of vitamin A. 

Recommended Dosage
The RDI for vitamin A is 1000ug (micrograms) of retinol, equal to 3333iu (international units). The vitamin is currently measured by its active level in retinol and this is expressed in micrograms, while until recently the scale used was international units. One microgram is equal to 3.3 international units.
To obtain one microgram of vitamin A from betacarotene, a pro-vitamin form that must be converted by the body, 6ug of betacarotene are required, but betacarotene is also a good antioxidant and is non-toxic in significant quantities.
Pregnant women should be careful to avoid supplements containing more than 3000ug (10,000iu) of retinol or preformed vitamin A, as this could cause foetal damage.

Best Natural Sources
The richest sources of vitamin A (measured by retinol content) include the following:

100g fried liver	10,700ug		1 tin sardines	259ug
1 tbsp cod liver oil	4080ug		1 cup tomato puree	240ug
29g chopped liver	2350ug		1/2 cup bran	225ug
1/2 cup raw carrot	1715ug		1 cup vitamin A enriched milk	139ug
1 cup pumpkin	1435ug		1 tbsp pate	130ug
1 cup boiled cabbage	962ug		85g cooked lambs livers	116ug
1 mango	805ug		1 tbsp margarine	112ug
1 cup tinned veg soup	588ug		1/2 cup broccoli	108ug
1 cup melon	500ug		1 tbsp butter	107ug
1 cup apricot in syrup	412ug		1 fried egg	84ug
1/2 cup boiled frozen veg	280ug

                       
Source:Nicola Reavley. New Encyclopedia Vitamins, Minerals, Supplements & Herbs.Bookman Press Pty Ltd. 1998.

Better Performance With Vitamin A
As we said at the top, vitamin A does not directly increase strength or muscle size but it does help maintain peak health and that undeniably contributes to better performance and more growth. And although deficiency is uncommon in developed countries, since vitamin A is present in a wide variety of foods, it’s worth noting that research shows that athletes often lack vitamin A, and especially bodybuilders, because of their extreme physical expenditure and restricted diets that do not include sufficient fat to ensure proper absorption.
Optimum vitamin A levels can guarantee growth without problems, prevent respiratory tract infections, improve recovery from soft tissue injury and strengthen the immune system. In addition, to get sufficient vitamin A nothing more is needed than a balanced diet that includes a little fat, and if you follow a diet very restricted in fatty acids then simply incorporate a multivitamin that includes vitamin A into your nutritional plan to guarantee peak performance.