Ascorbic acid vitamin minimum

Ascorbic acid is very soluble in water and mainly excreted in the urine. No ascorbic acid is excreted during vitamin C deficiency. A minimum amount is lost in the feces, even after intake of gram dosages (154). 

Other investigators have found larger amounts of ascorbic acid were necessary to maintain normal concentrations of the vitamin in blood. For monkeys, 10 (63) and 25 (35) mg of ascorbic acid/kg of body weight were proposed as the minimum required amounts. Recent experiments showed that the trained monkey required only 3-6 mg of ascorbate/kg of body weight (120). Young monkeys (sexually imma-... 

Since the discovery of ascorbic acid and its identification with vitamin C there has been continued effort to determine the human requirement for this essential nutrient. Evidence indicates that the minimum daily intake needed to prevent scurvy is about 10 mg. The daily allowance recommended by health authorities for adults ranges from 20 mg in the United Kingdom to 75 mg in West Germany. The Food and Nutrition Board of the U.S. National Research CounciP recommends values ranging from 35 mg for an infant to 60 mg for a 70-kg man, as designed for the maintenance of good nutrition of practically all healthy people in the U.S.A. The recommended allowances are said to provide a generous increment for individual variability and a surplus to compensate for potential losses in food. 

The minimum vitamin C requirement to prevent the development of scurvy has been found to be 10 mg/day (Hodges et al., 1971). This supply is not sufficient for the provision of acceptable reserves of the vitamin. The intake of 10 mg ascorbic acid per day reflects a plasma concentration of 7.6-14.1 p,mol/liter (0.13-0.24 mg/100 ml), a concentration that is far from tissue saturation. The renal clearance of ascorbic acid rises sharply at a point of 82 xmol/liter (1.4 mg/100 ml). An adequate plasma level of 44 p.mol/liter (0.75 mg/100 ml) can be maintained by a daily supply of 60-75 mg ascorbic acid. The daily amount of ascorbic acid, which is catabolized by the human body, can be calculated to be 60 mg based on a total body pool of ascorbic acid of approximately 1500 mg and a maximum turnover rate of 4%. These data are the scientific basis for the formulation of the above recommendations to meet the physiological needs. Table IV shows the recommended daily vitamin C intake for different population groups from the different societies that issue such recommendations. 

A daily intake of 10 mg of ascorbic acid will prevent scurvy. But this should be regarded as a minimum level. In order to provide for individual differences and margins of safety, the Food and Nutrition Board of the National Academy of Sciences recommends the following allowances 30-35 mg for infants, 40-45 mg for children, 60 mg for males and females over 14 years, 70 mg for pregnancy, and 95 mg for lactation. (See the section on VITAMIN [S], Table V-5, Vitamin Table.)... 

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