Vitamin B 6 depletion in man: blood vitamin B 6, plasma pyridoxal-phosphate, serum cholesterol, serum transminases and urinary vitamin B 6 and 4-pyridoxic acid
Baysal, A.; Johnson, B.A.; Linkswiler, H.
Journal of Nutrition 89(1): 19-23
A daily diet containing 0.16 mg vitamin B6, 100 g protein and with fat providing 40% of the energy was given to 6 normal male students for 50 days. Daily supplements of 0.6 or 0.9 mg pyridoxine were given when disturbance of tryptophan metabolism indicated vitamin B6 deficiency (Abst. 4460, Vol. 35) and 50 mg pyridoxine was given on the last 3 days of the experiment. Depletion of vitamin B6 gave a rapid decrease in excretion of vitamin B6 and after 5 days concentrations of vitamin B6 in blood were 20% of the values before depletion. There was no vitamin B6 in blood or 4-pyridoxic acid in urine after depletion for 25 days. Plasma pyridoxal phosphate also decreased after vitamin B6 depletion and the transaminase activities, especially that of serum glutamic pyruvic transaminase, were low. Vitamin B6 in blood and urine and 4-pyridoxic acid in urine were increased by supplementation with 0.6 or 0.9 mg pyridoxine but restoration of the transaminases and plasma pyridoxal phosphate required 50 mg pyridoxine. There was no change in serum cholesterol.