2. Vitamin B12/ Folate
This supplement is needed to make neurotransmitters which are needed for the nervous system to work properly. Also, this vitamin is vital for pregnant women as a lack of folate can lead to neural tube defects in the fetus. In adults, a deficiency of folate or folic acid can cause mood problems and depression. Other symptoms include fatigue, insomnia, anemia and other mental and physical health issues.