is a naturally occurring form of folic acid. The bioavailability of dietary folate may be hampered by the need of the glutamate moieties to be deconjugated before absorption. Folate deficiency in humans leads to anemia, neural tube defects and, possibly, chronic diseases such as cardiovascular disease, colon cancer, and neurocognitive dysfunction. Folate status is ascertained not only by the intake of folate but also by its bioavailability. Bioavailability is defined as the proportion of ingested folate that is absorbed and available for metabolic processes and storage. In humans, the bioavailability of folate from the diet is assumed to be {approx}50%, whereas the bioavailability of synthetic folic acid used in supplements and as a food fortificant is estimated to range from 76% to 97%. Patients with pernicious anemia in relapse and postgastrectomy macrocytic anemia cannot readily utilize for hematopoiesis a naturally occurring conjugate of pteroylglutamic acid although they respond promptly to administration of the free vitamin. This effect varies in different patients. Inability to utilize the conjugated vitamin appears to depend at least in part upon a conjugase-inhibiting substance present in natural sources of conjugate. References: Melse-Boonstra A, Verhoef P, West CE, van Rhijn JA, van Breemen RB, Lasaroms JJ, Garbis SD, Katan MB, Kok FJ. A dual-isotope-labeling method of studying the bioavailability of hexaglutamyl folic acid relative to that of monoglutamyl folic acid in humans by using multiple orally administered low doses. Am J Clin Nutr. 2006 Nov;84(5):1128-33. PubMed PMID: 17093166.

纯度：≥98%

CAS：35409-55-3