Dairy Chemistry And Biochemistry

VITAMINS IN MILK AND DAIRY PRODUCTS^283

CHaOH

I

HO CHpOH

HsC

Pyridoxine

CHaOH

6.27 "0

H3C

Pyridoxal

CHz-NHz

CHaOH

6.28 "0

H3C

Pyridoxamine

o* .H

0 CHrNH2 0

"0 -f:o $l_ Hoe HaO-P-0 II I

0

6.29 I

H3C / 7 H3C /

Pyridoxal phosphate NH3 Pyridoxamine phosphate

functions and immune response. High doses of vitamin B,, often associated
with excessive intake of supplements, are toxic and can cause bloating,
depression, fatigue, irritability, headaches and nerve damage.
Since vitamin B, is essential for amino acid (and hence protein) metab-
olism, its RDA is quoted in terms of protein intake (0.016 mg per g protein
per day, equivalent to about 2.0 and 1.6mgday-' for men and women,