Health Mail Vol.1 Issue 3 Title : Introduction to Vitamins 1/1
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Introduction to Vitamins
Polish Chemist Casimir Funck coined the term vitamin in 1910 after isolating from rice a substance curing the disorder beriberi. He called the substance 'vital amine' which then became vitamin.
As other substances were isolated over the following decades the number of vitamins grew (and shrank, as some vitamins were relegated to 'vitamin-like substances').

The name of a vitamin is a letter representing a group of chemical compounds (e.g. vitamin A, vitamin B). A number to distinguish between the various subgroups of chemicals then follows this letter (e.g. vitamin B12). There may be a further subdivision, where a lower case letter is added to the name (e.g. vitamin B12b).

The presence of all vitamins is essential to a healthy physiology. They perform a variety of vital functions within the body e.g. as cofactors for enzymatic reactions.
A severe defieciency, or avitaminosis, causes some form of disease. Each type of vitamin deficiency is associated with its own disease (deficiency of vitamin D leads to rickets, of vitamin C to scurvy and of vitamin A to blindness).
Deficiencies also have subtler influences on health the importances of which have not always been understood. For example UNICEF mentions that vitamin A is essential for a child's immune system to function properly as it improves resistance to disease, and is key to improving a child's survival, growth and development. It then goes on to state - "In the past, vitamin A deficiency (VAD) has been seen solely as a cause of blindness, and in many countries, vitamin A activities are still limited to blindness prevention"(6).

As a rule, vitamins cannot be synthesized at all or in large enough quantities in the human body and must be supplied from the environment through diet. Just as with carbohydrates, it is possible to construct 'food-chains' for vitamins, starting with bacteria or yeast.

Vitamins can be said to be associated with various illnesses in 3 ways:

  1. Problems are caused by a lack of a vitamin (vitamin deficiency or avitaminosis)
  2. Problems are caused by an excess of a vitamin (vitamin toxicity or hypervitaminosis)
  3. A vitamin is used for therapy (high dosage for a limited time span)
  4. Other uses - e.g. E300 or vitamin C is used as an antixodant (browning inhibitor of cut fruit; improving agent for four; meat colour preservative); E375 or vitamin B3 is used as a colour protector

Just as with other nutrients, when dealing with vitamins the following factors are important yet often ignored when it comes to determining requirements (2)-
  1. bioavailability
    • degree with which a substance becomes available to the target tissue after administration:
    • Processing and refining can alter digestibility and absorption
    • Other substances may inhibit or enhance processing
    • Many people have individual conditions of malabsorption
  2. inborn errors in metabolism
    The term refers to an error in a single gene causing a metabolic pathway to break down. With regard to vitamins such defects can be -
    • an enzyme requiring a specific vitamin in order to function
    • a defective absorption of a vitamin
    • an inability to transport a vitamin
    • an inability to convert a vitamin to its active form
  3. losses in food processing
    covers industrial food processing as well as cooking at home and deals with losses which are incurred when food is boiled or fried. It should be noted that some processing techniques can also enhance bioavailability by destroying vitamin inhibitors.
  4. vitamin/mineral relationship
    vitamins and minerals need each other to complete a function. E.g. vitamin D is essential for absorption of calcium; calcium is essential for absorption of B12.

It is common practice to divide vitamins into 2 groups:
  1. Water soluble
    main vitamins are those in group B (e.g. B1, B6). These vitamins are generally enzyme co-factors and are important for the energy metabolism. Being water soluble, excess amounts of vitamins can easily be secreted. A disadvantage with this form of secretion is that the body doesn't want to or cannot discriminate between the different types of vitamin B it is secreting. The result is that an excess of one vitamin can cause a deficiency in other vitamins due to indiscriminate secretion.
  2. Lipid soluble and insoluble in water
    important vitamins in this group are A, D, E, K. They are not generally enzyme co-factors and they have nothing specifically to do with energy metabolism.
    Because they are insoluble in water these vitamins can be stored in the body. This means a deficiency only occurs after a considerable period of deprivation. It also means that it is difficult to get rid of excess amounts of the vitamins and it is easy for toxic conditions to arise (    5). The only way to eliminate the vitamins is via the gallbladder.


A table of vitamins and vitamin-like substances

For this article we wanted to produce a simple table of all the vitamins and vitamin-like substances. This turned out to be a more difficult exercise than expected, as there seemed to be some disagreement about the more obscure vitamins. Table 1 lists all the vitamins (past and present) we could find.

Table 1. A list of Vitamins         
Grouping Description
A   retinol (animal origin), carotin (plant origin) other names: axerophthol, biosterol, rinyl palmitate, retinyl acetate, retinal, carotene, carotenoids
B B1 thiamin, thiamine, aneurine
  B2 riboflavin, beflavin, lactoflavin
  B3 niacin, nicotinic acid, nicotinamide, nicotinate, pyridine-3-carboxylic acid
  B4 Binet: adenine. Mervyn: this is no longer classified as a vitamin
  B5 pantothenic acid
  B6 pyridoxine, pyridoxal, pyridoxamine
  B7 Binet: either vit I or vit.J. Mervyn: unnamed vit. For microorganisms
  B8 Mervyn: vit. For microorganisms. Binet: biotin. Mervyn and Geddes: biotin is vitamin H
  B9 Nielsen, Binet, Geddes: folic acid, folacin, pteroyl-L-glutamic acid. Mervyn: unnamed vit. For microorganisms
  B10 Binet, Nielsen: para-aminobenzoic acid. Mervyn: unnamed vit. For chicks. Mervyn, Geddes: paba is vit. Bx
  B11 Binet, Geddes: carnitine. Mervyn: unnamed vit. For chicks. Carnitine is vit.Bt
  B12 cobalamin, cobanamide, dibencozide, cyanocobalamine
  B12b Geddes: hydroxo-cobalamin
  B12c Geddes: nitrito-cobalamin
  B13 orotic acid, uracil 6 carboxylic acid
  B14 Binet: xanthopterine (in-soluble in water). Meyer: derivative of B12
  B15 pangamate, pangamic acid
  (B16) No record found (?)
  B17 amygdalin, laetrile. Mervyn does not regard this as a B vitamin
  Bc Mervyn: the name for folic acid. Binet: another name for B9
  Bt Mervyn: the name for carnitine. Binet: another name for B11. Mervyn also no longer regards carnitine as a vitamin
  Bx Mervyn, Geddes:para-aminobenzoic acid (see B10). Geddes: this is a vitamin-like substance
C   ascorbic acid
  C1 Binet: ascorbic acid
  C2 Binet: same as vit.P
D   calciferol
  D1 Geddes: steroid alcohols
  D2 ergocalciferol, calciferol. Animal source
  D3 cholecaliferol. Found in yeast
E   tocopherols - alpha, beta, gamma and delta forms
F   Binet: linolic acid. Mervyn: no longer a vitamin
G   Mervyn, Geddes: B2. Binet: B6
H   Geddes, Mervyn: the name for biotin. Binet: another name for biotin - see B8
  H1 Binet: B8 (biotin)
  H2 Mervyn: procaine; no longer regarded as a vitamin. Binet: B10 (PABA)
  H' Binet: B10 (PABA)
I   inositol, bios I, lipotropic factor. Mervyn: vit.B. Geddes: vitamin-like substance
J   choline. Mervyn: vit.B. Geddes: vitamin-like substance
K   quinones
  K1 phytomenadione, phyloquinone, phytylmenadione Can be produced by bacteria in Intestines
  K2 menaquine Can be produced by bacteria in Intestines
  K3 menadione, menaphtone. Synthetic product
L L1 Binet: same as B9
  L2 Binet: same as B12
M   Binet: stigmasterol
N   thioctic acid, lipoic acid. Classified as vit. N by Binet, Geddes: synthesied by man, used to be a B vit.
O   Binet: same as B11
P   bioflavanoids, rutin,citrin,hesperidin. Mervyn: no longer regarded as a vitamin
PP   Mervyn: nicotinic acid. Binet same as B3
T   Mervyn: tegotin /termitin / factor T. Binet: same as B11
U   Mervyn: anti-ulcer substance. Mervyn: no longer regarded as a vitamin
Vitamin Like substance Ubiquinone, co-enzyme Q, co-enzyme Q10. depends upon vit.E
Vitamin Like substance lecithin, phosphatidylcholine. Choline (vit.J), inositol (vit.I) form a part of lecithin
Nielsen (1), Mervyn (2), Binet (3), Geddes (4)

References:
  1. "Biologisk Regeneration" by Kurt Winberg Nielsen, 1981
  2. "Thorsons Complete Guide to Vitamins and Minerals" by Leonard Mervyn, 2000
  3. "Vitamine et Vitaminothérape" by Dr Claude Binet, 1981
  4. "Vitamins & Minerals", published by Geddes and Grosset, 1999
  5. "What are Vitamins" by Betty Walsh , 1995
  6. UNICEF on vitamin A

Further Reading:

  
 
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