Tuesday, July 3, 2007

Dietary sources of Vitamin B6

Vitamin B6 is present in all natural unprocessed foods,
with yeast extract, wheat bran and liver containing
particularly high concentrations. Other important
sources include whole-grain cereals, nuts, pulses, lean
meat, fi sh, kidney, potatoes and other vegetables. In
cereal grains over 90% of the vitamin B6 is found in
the bran and germ (Polansky & Toepfer, 1969), and
75–90% of the B6 content of the whole grain is lost in
the milling of wheat to low-extraction fl our (Sauberlich,
1985). Thus, white bread is considerably lower in
vitamin B6 content than is whole wheat bread. Milk,
eggs and fruits contain relatively low concentrations
of the vitamin.
In raw animal and fi sh tissue the major form of
vitamin B6 is PLP. Apart from very low concentrations
in liver, PN and PNP are virtually absent in animal
Plant tissue contains mostly PN, a proportion of
which may be present as PN-glucoside and/or other
conjugates. PN-glucoside has not been found in
animal products. No generalizations can be made
as to one group of foods consistently having a high PN-glucoside content. Typical sources of PN-glucoside
(expressed as a percentage of the total vitamin B6
present) are bananas (5%), raw broccoli (35%), raw
green beans (58%), raw carrots (70%) and orange juice
(69%) (Gregory & Ink, 1987). PN-glucoside accounted
for 10–15% of the total vitamin B6 in the typical mixed
diets used in an American human study (Gregory et al.,
1991), but would be proportionally higher in vegetarian

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