Norwegian scientists found that high doses of folic acid (0.8 mg/day) and VitB12 (0.4 mg/day) increased the risk of cancer and death in patients with ischemic heart disease.

Folic acid is often used to prevent fetal neural tube malformation, and its role in the prevention of some cancers, such as drinking female breast cancer, but at this time its dosage is not large, more than 0.4 mg, 0.5 mg

The researchers randomly assigned nearly 7,000 patients with ischemic heart disease to take either a B vitamin (folic acid, vitamin B12) or a placebo. The results showed that the rates of new cancer, cancer mortality and all-cause mortality were 10.0% vs. 8.4% in the folic acid and vitamin B12 group and the control group, respectively.4.0% vs 2.9%;16.1% versus 13.8%.

Those who received folic acid and vitamin B12 had a 21% increased risk of cancer, 38% increased risk of cancer death, and 18 % increased risk of all-cause death, compared with the control group.

The Norwegian study suggests that high doses of folic acid and vitamin B12 increase the risk of cancer and death in patients with ischemic heart disease and that the same effect in other populations remains to be determined.