Q1) Why does Shaklee use folic acid, instead of the form of this B vitamin (B9) found in foods?
Answer 1) Folic acid is more bioavailable and stable than food folate, and most of the clinical studies tested folic acid, rather than food folate, for the effect on health benefits.
Folic acid is one of many forms of vitamin B9. On a gram-for-gram basis, folic acid delivers twice as much B9 when compared to food folate, according to the Dietary Reference Intake (DRI)* by Institute of Medicine (IOM). This recommendation is based upon many research results on bioavailability, indicating that folic acid is more bioavailable than food folate.1
(*Dietary folate equivalents: 1 µg food folate = 0.6 µg of folic acid from fortified food or as a supplement consumed with food = 0.5 µg of a supplement taken on an empty stomach.)
Linus Pauling Institute, one of the leading academic nutrition research institutes in the world, also indicated that bioavailability of food folate is limited and varies from one food matrix to another; further supporting folic acid is more bioavailable than food folate.2 We encourage consumers to consume foods such as beans, lentils, and dark green leafy vegetables, such as spinach that are good sources of folate;3 but for supplementation and fortification, folic acid is the primary choice.4
No dietary supplements that we are aware of use folate actually derived from food; some use synthetic methyl folate,2 i.e., L-5-Methyl-tetrahydrofolic acid, in the form of a calcium salt.