Vitamin B-6, or pyridoxine, plays a variety of important roles in your body. Similar to the other B-vitamins, vitamin B-6 helps your body convert food energy into glucose, metabolize fats and proteins, and ensure proper function of your nervous system. With these various effects, there are ways in which your vitamin B-6 status may cause or contribute to your sleeping difficulties, or insomnia.
Tryptophan is an essential amino acid that helps regulate nervous system activity related to relaxation and sleep. Vitamin B-6 converts a small amount of the tryptophan in your body to niacin, or vitamin B-3, and serotonin, a neurotransmitter that helps regulate sleep patterns. By failing to obtain an adequate amount of vitamin B-6 in your diet, your body's metabolism of tryptophan may be disturbed. This may limit the amount of serotonin in your body, potentially leading to disturbed sleep patterns and insomnia.
Due to its role in converting tryptophan to niacin, a vitamin B-6 deficiency may cause or contribute to a deficiency in this important B-vitamin. Playing a variety of roles similar to those of vitamin B-6, the side effects of a niacin deficiency vary. While severe niacin deficiencies are rare, side effects include skin lesions, digestive problems, neurological disorders, fatigue and insomnia.
Clinical depression can have contradictory effects on your sleep cycle, leading some to sleep excessively while contributing to sleep difficulties in others. Listing depression as a cause of insomnia, the National Sleep Foundation explains that the depression and insomnia are closely related, creating a vicious cycle. You can't sleep because you're stressed, and you're stressed because you can't sleep. Similar to its link to niacin, a deficiency in vitamin B-6 may contribute to the chemical imbalances related to depression. With vital roles in the production of dopamine and conversion of tryptophan to serotonin, the Office of Dietary Supplements links vitamin B-6 status to depression, potentially contributing to sleep difficulties.
Vitamin B6 Toxicity
While a deficiency in vitamin B-6 can contribute to sleep difficulties, overmedication with B-6 supplements may make your insomnia worse. In a 2003 study, Aliya Chaudary and her colleagues at London's Institute for Optimum Nutrition found that vitamin B-6 is one of the few water-soluble vitamins with potentially toxic effects. Linking excessively toxic levels of vitamin B-6 to insomnia, the researchers point out that insomnia symptoms are most readily treated by a reduction in B-6 intake over time. As vitamin B-6 may be linked to insomnia at both excessive and inadequate doses, it is best to consult your doctor before attempting to self-medicate with vitamin B-6.
- National Institutes of Health Office of Dietary Supplements: Vitamin B6
- International Neurology: A Clinical Approach; Robert P. Lisak
- The Merck Manual Home Health Handbook: Niacin (Nicotinic Acid)
- National Sleep Foundation: Can't Sleep? What To Know About Insomnia
- Journal of Orthomolecular Medicine: Indices of Pyridoxine Levels on Symptoms Associated with Toxicity: A Retrospective Study
- Duke Health: A Vicious Cycle: Insomnia, Anxiety and Depression