Ascorbic acid requirement and assessment of ascorbate status in the common marmoset (Callithrix jacchus).

Marmosets can tolerate an ascorbic acid (AA) deficiency for several weeks without clinical symptoms. After being fed an AA-free diet for 3 months, nonspecific deficiency symptoms became obvious. Different dietary levels of AA resulted in corresponding serum ascorbate levels. The kidney threshold of AA in marmosets is comparable to that in humans. When the minimal AA requirement is defined as the amount that is necessary to maintain a serum AA level above the kidney threshold, then about 20 mg AA/kg body weight is needed. This intake was achieved in our trial with a diet containing 500 ppm AA. Thus, the AA requirement of marmosets is severalfold higher than the AA requirement of humans.