29) Sleep Med. 2008 Jan; 9(1): 27–32.

Vitamins and Sleep: An Exploratory Study

Kenneth L Lichstein, PhD,* Kristen L Payne, MA, James P Soeffing, MA, H Heith Durrence, PhD, Daniel J Taylor, PhD, Brant W Riedel, PhD, and Andrew J Bush, PhD

Abstract

One-third of the United States population takes a vitamin or mineral supplement daily1. The booming nutritional supplement industry is predicated on consumers’ beliefs that these products produce health enhancement. Claims for sleep improvement have been advanced for a variety of such products as typified by valerian, for which there is evidence of mild efficacy2. Little or weak evidence exists to support soporific claims for other nutritional supplements3.

The majority of sleep enhancement products are classified as nutritional supplements. Minerals and vitamins have not been reported to have soporific effects, although B vitamins have been advanced as a preventive for insomnia based on research that suggests deficiencies in vitamin B6 promote psychological distress and ensuing sleep disturbance.

Although the direct link between vitamins and insomnia is unclear, there are studies that show an association between vitamins and other sleep disorders. Studies have reported that B-12 shortens the length of the sleep-wake rhythm5 and affects the circadian aspect of sleep propensity6. Studies have also identified vitamin B complex as a helpful treatment of nocturnal leg cramps7. Deficiencies in iron may be related to restless leg syndrome or periodic leg movement disorder8, both of which may have an effect on sleep maintenance. Evidence from these studies points to the possibility that sleep may be affected by vitamin and mineral intake or lack of these substances.

The presence of vitamins and other nutritional supplements has been known to have negative side effects, as well. For example, high doses of vitamin D have led to symptoms such as nausea, vomiting, and depression9. High doses of vitamin A have been associated with bone loss10. The finding of both positive and negative effects associated with vitamin use invites the question: Are there sleep effects associated with vitamins? A literature search revealed no studies addressing this question. Given this research gap, we conducted a preliminary investigation to determine if sleep-promoting or sleep-inhibiting effects are associated with common vitamins.