“Vitamin B12 deficiency can be slow to develop, causing symptoms to appear gradually and intensify over time,” said Harvard Medical School.
“It can also come on relatively quickly. Given the array of symptoms a vitamin B12 deficiency can cause, the condition can be overlooked or confused with something else.
“In many people, a vitamin B12 deficiency can be prevented. If you are a strict vegetarian or vegan, it’s important to eat breads, cereals, or other grains that have been fortified with vitamin B12 or take a daily supplement.
“A standard multivitamin delivers six micrograms, more than enough to cover the average body’s daily need.”