What it is
In 1951 Krebs and co-workers isolated a compound from seeds which
appeared to have vitamin activity. They named the product pangamic
acid (Greek: pan means universal, gamic or gamete implies a seed)
and it was assigned 15th position in the vitamin B series (vitamin
B15).
As a result of attempts by various research groups to synthesise
pangamic acid, two distinct products are now believed to be vitamin
B15. This has led to considerable confusion and lack of consistency
between experimental workers. Generally speaking Eastern European
workers are looking at a different pangamic acid than American
workers. Thus, claims for the successful use of pangamic acid
in Russia must not be confused with different claims in North
America.
Most workers agree that the material discovered by Krebs et al.
in 1951 is a secondary amino acid derivative of glucuronic acid.
Singh et al. (Indian J Pharmacol., 12, 48-49, 1980) identify the
vitamin chemically as d-gluconodimethylaminoacetic acid and confirm
that this product conforms in all respects (C, H analysis, infra-red
and NMR spectrum) to that reported by Krebs et al.
However, vitamin B15 has become one of the most sought-after items
in health food stores in the last five years and excessive claims
for its efficacy in human and horse nutrition have been made.
In particular a claim has been made that pangamic acid preparations
increase physical performance.
There appear to be at least four different products marketed in
the Western Hemisphere as pangamic acid:
- Equimolar mixtures of sodium gluconate and dimethylglycine.
- Di-isopropylamine.
- A mixture of di-isopropylammonium dichloracetate (57%), sodium
gluconate (29%) and glycine (14%).
- An extract from seeds said to contain 20% calcium pangamate.
In recent tests none of these products has been able to produce
any significant changes in the muscular endurance of rats.
However, since none of them appear to satisfy the chemical criteria
established by Singh et al. they may not have the vitamin activity
of pangamic acid as originally discovered.
What it does
Pangamic acid appears to be involved in lipid metabolism and has
a specific role in preventing the formation of excessive fatty
deposits. It appears to affect the rate of production and use
of cholesterol as well as triglycerides. This suggests a role
in preventing or controlling some fatty liver and vascular disease
problems. Since it also functions in the energy cycle it has been
suggested that it is important in the steady release of energy
for muscular activity. These effects relate to the stimulation
of the transmethylation reaction and tissue oxygen uptake.
Workers in Russia and India report that animals receiving diets
supplemented with vitamin B15 were more lively in appearance and
handling and showed increases in weight compared to controls.
They also showed remarkably increased endurance in swimming tests.
If insufficient is available
No actual deficiency disorder has been identified but, because
of its mode of action, it is reasonable to suppose that horses
receiving too little vitamin B15 would have a low threshold of
muscular endurance and have a disturbance of lipid metabolism
which might lead to excessive fatty deposits in essential organs
and vascular tissue. This could be important when horses are given
production diets high in fats.
If too much is given
Six months’ chronic toxicity studies using rats have shown pangamic
acid to be free from any undesirable effects.
Biosynthesis
While it has been found universally in seeds, brewers’ yeast and
other similar products containing a range of B-group vitamins,
there is no firm evidence of animal synthesis. While, by analogy
with yeasts, it seems likely that vitamin B15 could be produced
by microbial action, this has not been investigated or quantified.
How it is measured
At the present time the only methods for determining the pangamic
acid contents of feeds and animal tissues involve careful extraction,
purification and physical determination. The current method is
to extract all the vitamins of the B group and to separate B15
by thin layer chromatography on Kieselgel-G plates for determination.
Requirements and allowances
Much of the experimental work which has been undertaken so far
may be irrelevant since different products have been used in the
trials. If sources of true vitamin B15 are available, a suggested
allowance is 50 mg/kg diet.
Livestock conditions suggesting further needs
Animals showing excessive fatty deposits in organs and vascular
tissues might benefit from additional supplies of vitamin B15.
Horses forced to excessive activity may show improved strength,
endurance and fewer stress-related problems if given extra pangamic
acid. But care must be taken to supply true vitamin B15 rather
than the alternative homologues which do not appear to have the
same effects.
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