From the Guidelines
B vitamins, particularly B12, are crucial for individuals with hypothyroidism, as they support energy production, metabolism, and the conversion of T4 to T3 hormone. When considering B vitamins for hypothyroidism, it's essential to focus on the most recent and highest quality studies. According to a 2022 study published in Stroke 1, B vitamins, including B12, have been shown to reduce the risk of stroke by lowering homocysteine levels. This is particularly relevant for hypothyroid patients, as they may be at increased risk of stroke due to metabolic changes.
Key points to consider:
- B12 deficiency is common in patients with hypothyroidism, partly due to reduced stomach acid production and potential malabsorption issues.
- A B-complex supplement containing 100% of the daily recommended values, including B12, B6, and folate (B9), can help support energy production and metabolism.
- For B12 specifically, a daily dose of 1000-2000 mcg may be helpful if deficient, as suggested by the 2022 study 1.
- It's crucial to consult with a healthcare provider before starting any supplement regimen, especially if taking other medications, to ensure proper monitoring of thyroid levels and adjustment of treatment as needed.
In terms of specific recommendations, the 2022 study 1 suggests that supplementation with B vitamins, including methylcobalamin or hydroxycobalamin, is reasonable to reduce stroke risk, with a class 2a (moderate) recommendation. However, it's essential to prioritize the individual's specific needs and health status when making supplement recommendations.
From the Research
B Vitamins and Hypothyroidism
- B vitamins, particularly vitamin B12, play a crucial role in various bodily functions, including the production of red blood cells and the maintenance of the nervous system 2, 3, 4, 5, 6.
- Research has shown that there is a high prevalence of vitamin B12 deficiency in patients with hypothyroidism, with studies suggesting that approximately 39.6% to 68% of hypothyroid patients may have low vitamin B12 levels 2, 3, 4.
- The symptoms of vitamin B12 deficiency can be similar to those of hypothyroidism, including generalized weakness, impaired memory, depression, numbness, and decreased reflexes 2.
- Some studies have found a correlation between vitamin B12 deficiency and the presence of anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-Tg) antibodies in patients with hypothyroidism 3, 4.
- Vitamin B12 deficiency has been found to be more prevalent in females with hypothyroidism, with one study suggesting that 73.5% of vitamin B12 deficient patients were female 3, 4.
- Replacement of vitamin B12 has been shown to lead to improvement in symptoms in some patients with hypothyroidism, although a placebo effect cannot be excluded 2.
- The exact relationship between vitamin B12 deficiency and hypothyroidism is not fully understood, but it is thought that thyroid hormones may affect erythropoiesis, leading to anemia in vitamin B12 deficient patients 4, 5.
- A systematic review and meta-analysis found that patients with hypothyroidism had lower vitamin B12 levels than healthy participants, with a mean difference of -60.67 pg/mL 6.