“Don't use cyanocobalamin, a synthetic form of b12 that contains cyanide, requiring extra detoxification. Take methylcobalamin instead,” he suggests. Though oral vitamin B12 is generally safe ...

B12 is found mainly in animal products – meat, fish and dairy. (Dairy is important, even if you eat fish and meat, as it makes B12 more “bio-available”.) However, high-meat, low-veg diets ...