More specifically, the B-complex vitamins:

They support energy levels.
Maintain a healthy homocysteine ​​metabolism.
They promote the health of the nervous system.
All of the above help to address the symptoms and causes that cause anxiety, depression and cardiovascular disease.

B-complex vitamins are water-soluble. With the exception of B-12, they are in limited concentration in the body and therefore require daily replenishment. While B-12 is stored in the liver, the dietary sources are only of animal origin (meat, dairy), so supplementation of B-12 can be especially important for people on a vegetarian diet.

According to the international literature on preventive medicine, the necessary doses of B vitamins can never be obtained through diet alone, so it becomes necessary to take B-complex supplements in people who follow a strict vegetarian diet.