The thyroid is a small butterfly-shaped gland at the front of the throat below the voice box. It makes thyroid hormones that help the body produce energy and regulate temperature, among other physical and mental functions. Depression is a symptom of thyroid disease, primarily hypothyroidism. Prescribed medication is the standard treatment for thyroid disease, and nutrients in food and supplements are also beneficial in supporting thyroid function. Vitamin supplementation can help minimize symptoms of depression and fatigue caused by thyroid disease.
Folic Acid and Vitamin B-12
Deficiencies in both folic acid and vitamin B-12 are common in thyroid disease because systems that allow absorption of these vitamins are damaged due to low thyroid hormone production. The authors of "Encyclopedia of Natural Medicine," Murray and Pizzorno, describe folic acid and vitamin B-12 as methyl donors. Methyl donors nourish the brain in a process called methylation, which allows the neurotransmitters of the brain to signal each other properly. Vitamin B-12 and folic acid are involved with producing the "feel good" neurotransmitter dopamine. Supplementation of these two vitamins has had positive results in improving mood and alleviating depression, according to the authors.
Vitamin B-6
The neurotransmitters dopamine and serotonin depend on vitamin B-6 for synthesis. Many of the popular antidepressants, such as Prozac, are selective serotonin reuptake inhibitors, which stop the reabsorption of serotonin to the brain. Serotonin opposes dopamine by maintaining a "happy feeling" by calming and relieving anxiety. Dopamine helps people feel happy by becoming more talkative and energetic. Murray and Pizzorno state that the many depressed people on Prozac may be depressed simply as a result of low vitamin B-6. At the time of publication, the Linus Pauling Institute argues that there is not enough convincing evidence to show that vitamin B-6 supplementation is an effective treatment for depression.
Vitamin C
Vitamin C is involved with the synthesis of the neurotransmitter serotonin; specifically, the synthesis of tryptophan that is essential to making serotonin. Tryptophan is the amino acid that makes you feel sleepy after eating a big turkey meal. Low levels of serotonin are associated with depression. Researchers note in a May 2010 article in "Amino Acids" that tryptophan is a precursor to thyroid hormones.
Vitamin D
Vitamin D deficiency has been linked to seasonal affective disorder, which is depression caused during the winter months when there is little to no sun exposure. At the time of publication, the relationship between vitamin D and depression is not fully understood. According to a review published in August 2009 in "Nutrition Reviews," findings from clinical trials suggest that vitamin D does improve mild depression.
Low vitamin D levels are associated with Hashimoto's disease, an autoimmune thyroid disease. Datis Kharrazian summarizes in his book "Why Do I Still Have Thyroid Symptoms When my Lab Tests Are Normal?" several studies that show a vitamin D processing defect in 90 percent of people with autoimmune hypothyroidism. These individuals require higher amounts of vitamin D through diet or supplementation.
References
- "Nutrition Reviews"; Vitamin D and the Occurrence of Depression: Causal Association or Circumstantial Evidence?; Elizabeth Bertone-Johnson; August 2009
- "Encyclopedia of Natural Medicine, Revised 2nd Edition;" M. Murray and J. Pizzorno; 1998
- Linus Pauling Institute; Micronutrient Information Center - Vitamin B6; 2011
- "Amino Acids"; Tryptophan and Iodothyronine Transport Interactions in HepG2 Human Hepatoma Cells; James Ritchie and Peter Maving Taylor; May 2010
- "Why Do I Still Have Thyroid Symptoms When My Lab Tests Are Normal?"; Datis Kharrazian; 2010
- Institute of Medicine: Dietary Reference Intakes Chart; 2001
