Folate metabolism and in vivo radiofolate binding in normal, folate-deficient and folate-saturated subjects.

After ingestion of 14C-CH3 H4PteGlu by folate-deficient and folate-saturated subjects, and 14C-CH3H4PteGlu as well as 3H-PteGlu by a normal control subject, the dialysis-resistant (bound) plasma radiofolate fraction appeared increased in folate saturation and decreased in folate deficiency (compared with normal folate status).