Vitamin Supplements

During the formation of niacin from tryptophan yet another vitamin is needed and again it acts as a coenzyme. This is vitamin B6 and it is given the name pyridoxine. Of all the vitamins this is probably the greatest worker and it takes part in over sixty different metabolic reactions.

As we saw in the descriptions of NAD and FAD many coenzymes are involved in the transference of single atoms from one substance to another. Many reactions in the body require a greater change to take place and whole groups of atoms may be transferred between molecules. The enzymes which organise these larger changes are called transferases and the groups they transfer belong to certain chemical families. For instance, they may be methyl groups (these contain one carbon and three hydrogen atoms, CH₃) or they may be aldehydes (these contain one carbon, one hydrogen and one oxygen, CHO). Pyridoxine, our worker vitamin, is a specialist in assisting enzymes to transfer amino groups (NH₂) and it is therefore important in the building of protein structures from amino acids. The protein we eat is made from small units, the amino acids, and these are strung together in different sequences.

The protein of skin and muscle is different from the protein of hair and nails, but it contains the same collection of twenty basic amino acids but each in a different sequence. If we think of them as different coloured beads on a chain then it is easier to understand how they can be rearranged to give different patterns. Once the protein is digested in the intestines the amino acids are released from the chain and absorbed into the bloodstream as separate ‘beads’, but they join up again to form new proteins when they reach the cells of the body. The demand for particular types of protein within the body may require more of one type of amino acid than is currently available. Careful rearrangement of groups between the amino acids can alter their structure and characteristics and make up this deficit. This is happening all the time and pyridoxine, in the form of pyridoxal 5-phosphate, is the key vitamin or coenzyme in the process. Our need for pyridoxine is calculated according to the amount of protein we eat. One or two milligrams (1-2 mg) is enough for most people but a high protein diet could increase the demand for this vitamin.

The name ‘pyridoxine‘ covers the three forms of vitamin B6 (see Fig. 2). Pyridoxal and pyridoxamine are found in vegetables and plants, and pyridoxine is predominant in animal tissues. All three are interchangeable once they have been eaten and digested, and can therefore all be used to form the coenzymes that are needed. Although we tend to associate this vitamin with protein metabolism it is also used as an important coenzyme in the formation of neurotransmitters (nerve messengers) in the brain. A lack of pyridoxine has been known to cause convulsions and nervous disorders in young children. This type of deficiency is unlikely, but if the vitamin is not well absorbed or if it is affected by certain medical drugs then some shortage can be felt.

A low intake of pyridoxine can also produce a form of anaemia because haemoglobin cannot be made in adequate amounts for the new blood cells. Haemoglobin contains protein and its structure is formed with the help of vitamin B6 as a coenzyme. If there is too little haemoglobin in the body then oxygen transport from the lungs to the tissues becomes inefficient. Tiredness and a shortage of breath are typical symptoms of anaemia.

Possibly related posts: (automatically generated)
PYRIDOXINE (B6)

• What are vitamins, are they organic?
• The pseudo-vitamins (CHOLINE)
• Mineral Supplements, how safe is your daily Minerals Intake? continued
• The B complex: RIBOFLAVIN (B2)
• The B complex: THIAMIN (B1)
• Vitamin Supplements, Safe daily dose of Vitamin Intake continued
• Vitamin C
• The Slimming Diet & Extra Vitamin
• Drugs and You continue...
• Nutrition supplements Vitamin B6 (pyridoxine) Health Merits