5⃣ What are the potential risks? Part 1 - Vitamin B12 deficiency As already mentioned above, it's acknowledged, even by those who support folic acid supplementation that it has some dangers. Both folate and vitamin B12 are needed for DNA synthesis in rapidly dividing cells. A shortage of either vitamin produces the same type of anaemia with the same set of symptoms. But vitamin B12 deficiency has another, less immediately obvious, symptom - nerve damage. If someone has undiagnosed vitamin B12 deficiency, folic acid supplementation can cause the more obvious short term symptom - the anaemia - to disappear leaving the nerve damage undiagnosed and untreated. This can ultimately lead to permanent, irreversible damage. patient.info/medication-inte… The NHS says folic acid supplementation may not be suitable for people with vitamin B12 deficiency or pernicious anaemia. That's great for people who already know they have B12 deficiency. But what if they don't? By taking folic acid supplements (or eating food with folic acid fortification). they may be inadvertently masking a more serious problem. And food containing folic acid doesn't come with big red stickers saying "DO NOT EAT IF YOU HAVE VITAMIN B12 DEFICIENCY, OR THINK YOU MIGHT". Maybe they should? 6/n