A thyroid condition can leave you with low energy, weight gain, brain fog and thinning hair. Optimizing your nutrient intake and taking thyroid-friendly supplements can support hormone balance, and provide thyroid symptom relief.
Vitamin C is an antioxidant that reduces oxidative stress, which may benefit thyroid function. Vitamins B6, D and E also support thyroid health by helping to absorb iron, which is often deficient in people with thyroid disorders.
L-theanine
L-theanine is a nonprotein water-soluble amino acid found in green tea and is used as an oral dietary supplement for its perceived antioxidant and relaxing effects. It is also considered to have neuroprotective, anti-inflammatory, and antidiabetic effects. It can also enhance chemotherapeutic effects and reduce toxicity in cancer cells. However, its effects on cognitive function have not yet been fully understood. In a recent study, we evaluated the effects of a single dose of L-theanine on cognitive functions using Cognitrax tests in middle-aged people. In the experimental group, a single dose of L-theanine significantly improved attentional performance and relaxed mental state, but did not affect other cognitive functions. In the control group, there was no effect of a single dose on these outcomes.
Another study demonstrated that L-theanine could significantly improve intestinal integrity in rats with E44813 bacterial enterotoxin-induced colitis by inhibiting the activation of NF-kB and downregulating the expression of proinflammatory cytokines. It also stimulated the proliferation of intestinal epithelial cells and increased villus height and crypt depth. Moreover, it significantly enhanced the synthesis of glutamine and reduced the levels of enterotoxin in intestinal mucus.
In the rat model of spinal cord injury, it has been reported that L-theanine can promote recovery of behavioral motor function through the inhibition of posttraumatic oxidative stress, neuroinflammation, and apoptosis (40). In addition, in a brain injury model caused by intraperitoneal administration of reserpine, L-theanine was found to protect the hippocampus and cortex by reducing the levels of oxidative damage and downregulating the expression of inflammatory cytokines (41). L-theanine can also promote nerve regeneration in a model of brachial plexus root avulsion created in Sprague Dawley rats. In this study, L-theanine and cystine enhanced the synthesis of glutathione in the brain and accelerated the nerve regeneration in the injured rats by inhibiting oxidative stress and regulating the activation of SOD, GSH, and CAT activity (42).
Vitamin D
Vitamin D is a crucial micronutrient that acts as a molecular cofactor, metabolic regulator, gene expression modulator, and epigenetic modifier. In addition, it is closely related to the occurrence and development of thyroid diseases (including autoimmune thyroiditis, hyperthyroidism, and thyroid cancer). Its regulatory functions are mainly achieved through interaction with nuclear receptor VDR. Accumulating evidence shows that elevated serum vitamin D concentrations can significantly inhibit the occurrence and progression of thyroid cancer by suppressing gene transcription through DNA methylation, and inducing cell apoptosis and inhibiting cell invasion through the activation of cysteine-aspartic proteases (caspases) alongside other pro-apoptotic proteins.
In addition, it has been found that the expression levels of vitamin D receptor mRNA and protein are significantly decreased in papillary thyroid carcinoma (PTC) cells. It is suggested that this phenomenon might be associated with the VDR polymorphisms, which have been shown to affect the ligand-binding affinity and/or transcriptional activity of VDR and thus influence its transcriptional regulation.
The deficiency of vitamin D can lead to decreased immunity, which is a common cause of the inflammatory condition known as de Quervain thyroiditis. Calapkulu et al. [86] carried out a clinical study of 170 patients with de Quervain thyroiditis and 86 healthy people, and found that the concentration of 25-hydroxyvitamin D was significantly lower in those with DH than in the control group.
Vitamin D also exerts immunomodulatory effects in autoimmune thyroid diseases, such as Hashimoto’s disease and Graves’ disease. It enhances the innate immune response, inhibits the proliferation of Th17 cells and the production of proinflammatory cytokines from them, and restores the balance between Th17 and Treg cells in the thyroid gland. It can also improve the sensitivity of thyroid hormone to TSH, decreasing the TSH-THR ratio.
NAC
NAC (N-acetyl cysteine) is a precursor to glutathione, the body’s master antioxidant. Glutathione is involved in many crucial functions, including the breakdown of pollutants and toxins, protein S-glutathionylation, lipid metabolism and more. In addition, NAC has been shown to prevent mitochondrial dysfunction by increasing glutathione levels.
N-acetylcysteine has been used to treat several psychiatric disorders, such as schizophrenia, bipolar disorder, and substance use disorders (SUDs). It can improve depression, anxiety, and obsessive-compulsive disorder by decreasing oxidative stress, enhancing glutamate function in the brain, and reducing inflammation. However, results have been mixed and future studies with larger, better-powered trials will be important to understand how NAC can benefit these conditions.
In animal models, NAC has been shown to reduce neuronal stress by preventing oxidative damage, enhancing mitochondrial function and regulating NMDA receptors. It has also been shown to relieve neuropathic pain by reducing inflammatory cytokines and reversing oxidative damage to the nerve cells that transmit pain signals.
NAC is also a liver detoxifier and can be helpful in managing Hashimoto’s or hypothyroidism by supporting the glutathione pathway and increasing the availability of thyroid hormone to the cells. Taking NAC with thyroid-boosting foods, such as turmeric, garlic, and fish oil can boost the effects of this powerful antioxidant. However, NAC isn’t for everyone and should be taken under doctor supervision because it has a high sulfur content, enhances detoxification, and can interact with some medications. The best NAC product I’ve found is a 700mg capsule from Moss Nutrition that can be taken once or twice per day with food. This is a good supplement to take in conjunction with the methylation protocol as it helps optimize methylation and reduces the need for other supplements.
Vitamin B12
Your thyroid might be small, but it plays a huge backstage role in your body – regulating metabolism, temperature, heartbeat, and brain development. And for peak daily performance, it requires a precise mix of essential micronutrients – from iodine and selenium to vitamin B12, iron, omega-3s, amino acids and more.
Vitamin B12 is a key cofactor in the production of DNA and red blood cells, and it plays a role in maintaining thyroid health by promoting metabolism and supporting energy levels. It is also important for maintaining the protective sheath (myelin) that encases nerves, and low B12 can result in weakness and numbness/tingling. People with thyroid conditions often have lower stomach acid levels, which makes it harder to absorb vitamin B12 from food or supplements. In some cases, this can lead to an autoimmune disorder known as Pernicious Anaemia. Those with this condition may benefit from supplementing with higher doses of methylcobalamin, which is more easily absorbed than cyanocobalamin.
I have received many emails from readers who have started feeling better after digging into their root cause and restoring the nutrient depletions that are common in Hashimoto’s, including vitamin B12. Taking high-quality multivitamins that include folate, B vitamins, NAC and vitamin D can be a great way to help support thyroid function. Vitamin E is another key nutrient that can reduce oxidative stress, which can make symptoms worse in thyroid disorders. It is also a potent antioxidant that can protect against cellular damage and support healthy thyroid tissue. It can be taken in combination with other dietary antioxidants, such as selenium, to further promote healthy thyroid and immune response.