When concentration of these vitamins in serum
overtakes value of saturation in tissues, they are excreted through urine. That is the reason why it is so necessary
to enter these vitamins through food, even when for complete vitamin missing
few months may be needed(ascorbic acid) or years(B12). Excess of
these vitamins is quickly urined out of organism, so they usually aren’t toxic,
but there are data of unwished symptoms created by extreme high intake of
niacine, ascorbic acid or pyridoxine.
Hydrosoluble
vitamins are very often found in food.
Cereals, legumes, green leaves vegetables, meat and milk products are good
sources of these vitamins, except of ascorbic acid and vitamine B12.
Ascorbic acid is found in fresh fruit and vegetables. Vitamine B12 is
synthetized by microorganisms, it is infiltrated into animal tissues, so it is
found only in meat and milk products.
All
hydrosoluble vitamins function like coenzymes or cofactors in enzyme reactions, with the exception of C vitamin. Roles of these vitamins are tightly mutually
connected and few of them can have some function in same metabolic way or even
in the same enzyme complex. Due to that, miss of one vitamine in
nutrition can create negative influence to other vitamine usage or metabolism.
So illnesses caused by missing of only one vitamine from this group are rare.
“Athletes’ nutrition”, Marina Djordjevic Nikic
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