Be cautious of claims that sound too good to be true
Vomiting becomes more common at this stage, particularly if large meals, rich foods, or alcohol are consumed
Taking supplements, especially in high doses, can leave a metallic taste in your mouth, especially if they contain the following: A 2021 review suggests that you may also experience a metallic sensation after eating foods fortified with these minerals
Other ways to raise your B12 If injections are not right for you, there are other options: oral B12 tablets or sublingual drops, more B12-rich foods like fish, eggs, and fortified cereals, or a full weight loss program that combines nutrition, activity, and medical oversight
The Mayo Clinic notes that even at therapeutic mega-doses, side effects are uncommon and mild: headache, nausea, diarrhea, fatigue, and a tingling sensation in extremities