Question: what vitamins to take at night?
Answer: Vitamin D. The 'sunshine vitamin' is thought to influence both sleep quality and quantity, and studies have shown that Vitamin D deficiency is associated with less sleep overall and also, with more disrupted sleep. ... 
Melatonin. ... 
Iron. ... 
Calcium. ... 
Magnesium. ... 
Vitamin E. ... 
B vitamins. ... 
Valerian.