Miscellaneous B Vitamins - Information and Sources
There are a number of other water soluble organic substances which are sometimes reported to be essential food components. Indeed there are thousands of organic compounds found in food; a few of these are often classed with the B complex vitamins. These are not 'essential' in the direct meaning of the word as they can be synthesised from other food constituents in the body; however, for some of them, consuming them from food may be metabolically advantageous.
Choline works in conjunction with folic acid and its functions are in the structure of cell members, neurotransmitter synthesis and liver protection. It is essential for brain and neural tube development in the foetus and infants.
Choline is plentiful in our diets and is easy to obtain sufficient from eating a wide variety of foods. Good sources of choline include: liver, eggs, beef, cauliflower, beans, soya and tofu, almonds and peanut butter.
Inositol is readily available from the diet as over 99% of dietary inositol is absorbed. It is also widespread in the diet and can be made in the body. Inositol functions to transport fat in the body and is important for hair nourishment.
Deficiency of inositol is rare as it is abundant, absorbed so easily and can be made in the body. Major sources of inositol are liver, brewer's yeast, grapefruit, bananas, raisins, wheat germ, nuts and peanuts, brown rice and cabbage.
PABA – Para-Amino Benzoic Acid
PABA is also related to folic acid thus is often grouped with the B vitamins. It is known as the 'sunscreen vitamin' and is often found in topical sunscreen preparations, as it can absorb UV light. It corrects loss of pigmentation in skin and hair, prevents hair greying, protects the lungs from ozone damage, acts as a coenzyme in the utilization of protein, assists in the formation of red blood cells and enhances the formation of folic acid in the intestine.
Deficiency can result from a poor intake of dietary PABA as well as a poor diet in general so insufficient is made in the body. Deficiency symptoms include eczema, wrinkles, fatigue, irritability, depression, arthritis and bursitis.
Best natural sources of PABA are brewer's yeast, liver, whole grains and eggs. It can also be made by intestinal bacteria.
Vitamin B15 – Pangamic Acid
Very little is known about pangamic acid, although we know it is not a dietary essential as it can be synthesised in the body. It may be involved in blood cholesterol lowering and aiding protein synthesis.
Pangamic acid is present in brown rice, brewer's yeast, brown rice, whole grains, nuts, pumpkin seeds, sunflower seeds and sesame seeds.
Vitamin B17 – Laetrile
Laetrile is also known as amygdalin and although referred to as a vitamin, it is not really one by definition. There is a lot of research into its use as a treatment for types of cancer, although evidence is mixed. Foods high in laetrile include apricots (fresh, canned and dried) and black cherries.