Vitamin A

  1. Vitamin A

    Great article:
    I'm pasting the relevant parts:
    By Chris Masterjohn

    The dense forest of bodybuilding nutrition contains a paradox: the
    quantity of information available is abundant, but the wisdom of
    traditional diets to satisfy the primary concerns of bodybuilders is
    sparse and hard to find. Typical recommendations include very low-fat
    diets rich in protein foods like salmon and chicken.

    You will search in vain through mainstream men's health magazines to
    find so much as a mention of the importance of vitamin A to
    bodybuilding. Yet this nutrient is essential to muscle-building and
    may be the bodybuilder's most potent weapon. Vitamin A is necessary
    for the utilization of protein and the production of testosterone and
    other growth factors. In fact, one human study, discussed below,
    found the administration of vitamin A and iron to have results
    equivalent to the administration of testosterone itself. Rather than
    advocating the consumption of vitamin-A rich foods such as liver and
    natural food-based supplements such as cod liver oil, mainstream
    men's health writers are advocating diets very high in protein, which
    deplete vitamin A reserves, leaving one to wonder whether the
    athletes who resort to over-the-counter steroid supplements might be
    able to achieve similar results by consuming a traditional diet, rich
    in vitamin A.
    Vitamin A and Testosterone

    Abundant animal research indicates the importance of vitamin A to the
    production of testosterone. Vitamin A crosses the blood-testis
    barrier in its alcohol form as retinol, where it is stored in the
    Sertoli cells and converted as needed to its more biologically active
    form, retinoic acid. Experiments with rats show that greater
    concentrations of vitamin A in the testes increase basal testosterone
    secretion, as well as transferrin, which is responsible for the
    transport of iron; and a variety of growth factors including
    IGF-binding protein 4 (which transports IGF), androgen-binding
    protein (which transports androgens), transforming growth factor-beta
    (which causes cell growth but suppresses cancer) and steroidogenic
    acute regulatory protein (which is responsible for the transport of
    cholesterol into the mitochondria for its conversion to steroids).
    Vitamin A also decreases estrogen production in the male testes. Rats
    that are deficient in vitamin A experience decreased testosterone
    until the accessory sex organs atrophy, indicating that vitamin A not
    only aids in, but is essential to, testosterone production.1

    One experiment using guinea pigs, which corroborates the many
    experiments done with rats, found a decrease in plasma testosterone
    associated with a deficiency in vitamin A.2 A human study comparing
    the dietary intakes of 155 pairs of male twins found a correlation
    between testosterone levels and vitamin A intake.3

    The most compelling study is one that assigned 102 teenage boys with
    short stature and delayed puberty into four groups: a control, a
    testosterone-supplemented group, a vitamin A- and iron-supplemented
    group, and a group that received both testosterone and the
    nutritional supplementation. All treatments were effective in
    inducing growth and puberty, whereas the control group did not gain
    weight or begin puberty in the same period of time. What is most
    amazing is that the degree of growth acceleration was similar in the
    testosterone-treated group and the vitamin A-treated group. Pubertal
    onset occurred in 9-12 months in the testosterone group, and by 12
    months in the vitamin-A group.4

    This study suggests two things. The first is that the growth problems
    these boys experienced could have been avoided if their parents only
    had known the importance of serving a meal with liver on a weekly
    basis, as liver is very rich in both vitamin A and iron. The second
    is that, with equivalent hard work and dedication, athletes and body
    builders may be able to achieve similar results from their training
    by taking high-vitamin cod liver oil and eating foods rich in vitamin
    A on a regular basis as others receive from the common practice of
    supplementing with testosterone precursors.

    Vitamin A and Protein Utilization

    The utilization of protein requires vitamin A. Several animal studies
    have shown that liver reserves of vitamin A are depleted by a high
    dietary intake of protein, while vitamin A increases in non-liver
    tissues. One explanation for this is that adequate protein is
    necessary for vitamin A transport. In one study researchers fed
    radioactively-labeled vitamin A to rats on low-protein and
    high-protein diets, using the amount of radioactivity present in
    exhaled gases, urine and feces as a measure of the metabolism of
    vitamin A, and found that vitamin A is indeed used at a higher rate
    on a high-protein diet.6

    Vitamin A is not only depleted by a high intake of protein, but it is
    also necessary for the synthesis of new protein, which is the goal of
    the bodybuilder. Rats fed diets deficient in vitamin A synthesize
    protein at a lower rate than rats fed adequate vitamin A.7 Cultured
    skeletal muscle cells increase the amount of protein per cell when
    exposed to vitamin A and D, but not when exposed to vitamin D alone.8
    Eat Your Liver

    Bodybuilders and other athletes interested in gaining muscle have an
    interest in boosting their levels of testosterone and other growth
    factors and maximizing their utilization of protein and its
    incorporation into muscle cells. Typical recommendations usually
    include very high amounts of protein, but exclude foods like liver
    that are high in vitamin A, and low-fat recommendations all but
    banish vitamin A entirely from the diet by excluding foods such as
    full-fat milk. The combination of a high-protein diet that depletes
    vitamin A and a low-fat diet that fails to provide vitamin A is a
    clear recipe for deficiency of this vital nutrient. Exercises that
    elicit a high demand for testosterone, such as squats and deadlifts,
    are often recommended for muscle growth, but without vitamin A the
    body cannot meet that demand for testosterone. It's high time for
    athletes to forget the modern mantras and remember the dietary wisdom
    of the past, achieving a lean, muscular physique through traditional
    foods such as liver, egg yolks, full-fat milk, butter from grass-fed
    cows and cod liver oil.

  2. I bet a lot of bodybuilders are deficient in Vitamin A because many don't consume enough leafy greens.

  3. Vitamin A and apple cider vinegar got rid of my chronic cystic acne.

  4. ya I can say I am way low on my vitamin A. I plan to change that soon

Similar Forum Threads

  1. Vitamin C Pre-Workout?
    By YellowJacket in forum Supplements
    Replies: 63
    Last Post: 10-06-2014, 03:31 PM
  2. Excess Vitamin A Harmful
    By YellowJacket in forum Supplements
    Replies: 1
    Last Post: 01-25-2003, 07:54 PM
  3. Replies: 1
    Last Post: 01-23-2003, 01:50 PM
  4. Vitamin Source
    By DarCSA in forum Supplements
    Replies: 1
    Last Post: 01-08-2003, 10:26 PM
  5. vitamin e on cycle
    By sage in forum Anabolics
    Replies: 20
    Last Post: 12-03-2002, 04:35 PM
Log in
Log in