Vitamin B6 compounds, after conversion to the active coenzyme form, pyridoxal phosphate, function in a variety of enzyme reaction that are metabolically essential. The vitamin is naturally present in a wide variety of foods. The Recommended Dietary Allowance is 2 mg per day for adults and 2.5mg per day during pregnancy, although it has been suggested that an intake as high as 15 to 30mg per day may be desirable for women during pregnancy or those using oral contraceptives. Thus, the daily per capita "intake" of 0.2 mg of pyridoxine hydrochloride per day (0.003mg per kg per day for adults) resulting from its addition to foods may amount to no more than 10 percent of the total intake. Available data are inadequate, because of variations in consumption patterns, for estimating the greatest amounts of pyridoxine hydrochloride added to foods that may be consumed by individuals in various age groups beyond infancy. For infants, such variations are rare because a large percentage of the food intake may be derived from commercially prepared formulas fortified with pyridoxine hydrochloride. It is estimated that the largest consumption by infants of pyridoxine hydrochloride added to foods will be less than 0.1mg per kg body weight per day.
Oral administration of pyridoxine hydrochloride or pyridoxine base to experimental animals in doses of approximately 10mg per kg per day to more than 100mg per kg per day has not been associated with adverse effects, including effects on reproductive performance. Pyridoxine dependency has not been produced in offspring of animals given high doses of pyridoxine hydrochloride during pregnancy. The acute LD50 in animals generally ranges hydrochloride during pregnancy. The acute LD50 in animals generally ranges from 1000 to 6000mg per kg when administered orally. Patients with homocystinuria and other vitamin B6 dependency states have been given daily doses of 1 to 25 mg per kg per day for months without evidence of adverse reactions.
The Select Committee has no evidence that pyridoxine (ie., pyridoxine base) is added to foods in the United States. Even if it were, its safety threshold appears to be no different than that of pyridoxine hydrochloride.
In the light of these considerations, the Select Committee concludes that: There is no evidence in the available information on pyridoxine hydrochloride or pyridoxine that demonstrates, or suggests reasonable grounds to suspect, a hazard to the public when they are used at levels that are now current or that might reasonably be expected in the future.