Ray Peat on Vitamin B1

Vitamin B1: Rapid Effect on Irritability and Mental Clarity

"A particular type of irritability, sometimes accompanied by the feeling that the head is in a kind of fog, is often the result of a vitamin B1 deficiency. If that is the cause, it clears up within minutes after taking the vitamin. A magnesium deficiency is another common cause of irritability."

Nutrition For Women