Menadione nicotinamide bisulfite is a bioactive source of vitamin K and niacin activity for chicks

Young chicks were fed a vitamin K-deficient soybean concentrate basal diet containing graded levels of menadione from menadione nicotinamide bisulfite (MNB) or menadione dimethyl-pyrimidinol bisulfite (MPB) to assess prothrombin time as a function of menadione intake. Prothrombin time decreased linearly as menadione dose increased from 0 to 400 micrograms/kg. Multiple linear regression slope-ratio calculations indicated that both sources of menadione were of equal potency. To assess niacin bioactivity of MNB, graded doses of nicotinamide (0 to 5 mg/kg) from MNB or nicotinamide were added to a niacin-deficient diet based upon corn, corn gluten meal and vitamin-free casein. Weight gain increased linearly as a function of nicotinamide dose, and multiple linear regression analysis of weight gain as a function of supplemental nicotinamide intake revealed no significant differences in slope between the two sources of nicotinamide. Using excess doses, MNB was compared with MPB in acute (single crop intubation) or chronic (fed in the diet for 14 d) toxicity trials. With a single menadione dose of 1600 mg/kg body wt, weight gain in the subsequent 14-d period was reduced by MNB but not by MPB. Mortality rates of 25 and 17% occurred for MPB and MNB, respectively, at this dose level. Doses lower than 1600 mg/kg body wt caused neither morbidity nor mortality. When provided in the diet for a 14-d feeding period, menadione doses of 3000 mg/kg diet from MNB reduced gain, feed intake, gain:feed ratio and blood hemoglobin concentration. Menadione doses of 6000 mg/kg diet were required to produce morbidity of this type when MPB was fed.(ABSTRACT TRUNCATED AT 250 WORDS)