Although relatively uncommon in the U.S., low levels of vitamin B are another correctible cause of hair loss.
What to do: Like anemia, simple supplementation should help the problem. So can dietary changes. Find natural vitamin B in fish, meat, starchy vegetables, and non-citrus fruits. As always, eating a balanced diet plentiful in fruits and vegetables as well as lean protein and “good” fats such as avocado and nuts will be good for your hair and your overall health.