Optifer F Tablets are an Iron and Folic Acid supplement to correct low iron values, especially in pregnancy, and prevent iron deficiencies. It will not give side-effects such as stomach problems or queasiness like so many regular synthetic iron supplements. OptiFer F Tablet is a heme iron supplement that is easily absorbed (high bioavailability) through the heme-receptor located in the intestine. Due to the low dosing and high absorption rate, heme iron produces fewer gastrointestinal side effects. Furthermore, the foods or drinks you consume do not affect heme iron's absorption rate.