没研究，不知是否准确，仅供参考。

Thiamine

from：http://www.progressivehealth.com/vitamin-b-and-its-impact-on-sleep.htm

Thiamine is also known as vitamin B1. Because derivatives of thiamine are present as functional molecules in all cells of the body, thiamine deficiency can cause severe damage to all the organs of the body especially those in the nervous system.

Therefore, low thiamine levels can cause mental confusion, irritability, depression and weight loss.

Thiamine deficiency has been linked to a number of diseases include Alzheimer’s disease, loss of eyesight and the disease complex known as beriberi. Alcoholics and people suffering from diabetes are most at risk of thiamine deficiency.

In addition, thiamine deficiency can also be caused or sustained by magnesium deficiency.

The active form of thiamine is an essential cofactor in the enzymatic utilization of amino acid and sugars. In the central nervous system, thiamine is used in the synthesis of at least 2 neurotransmitters: acetylcholine and GABA (gamma aminobutyric acid).

The Dual Nature of Thiamine on Sleep

Because thiamine is involved in the production of GABA, it may help improve sleep. However, it should be noted that it is only a cofactor of an enzyme involved in GABA synthesis and not a precursor of the neurotransmitter. Therefore, improvement in sleep quality from thiamine supplementation is most likely modest at best.

However, since thiamine is linked to magnesium, thiamine supplementation can also improve sleep by preventing magnesium deficiency.

On the other hand, insomnia is one of the symptoms of long-term and/or high-dose thiamine supplementation.

Studies show that taking thiamine hydrochloride in daily doses higher than 5,000 mg can cause insomnia, headache, irritability and rapid pulse. In all cases reported, these symptoms disappeared when the dose of thiamine was reduced.

Therefore, high-dose thiamine should be avoided and low to moderate doses may help improve sleep.