From the Guidelines
Folate supplementation is crucial for individuals with thyroid disorders, particularly those with hypothyroidism, as it plays a significant role in thyroid hormone metabolism and synthesis, with a recommended daily intake of 400-800 mcg for adults. The connection between folate and thyroid function is complex, with folate participating in methylation reactions that affect thyroid hormone synthesis and metabolism [ 1 ]. Hypothyroidism has been associated with reduced folate absorption, while hyperthyroidism may increase folate utilization, potentially leading to deficiency.
Importance of Folate in Thyroid Function
- Folate is necessary for proper thyroid function, as it participates in methylation reactions that affect thyroid hormone synthesis and metabolism.
- Hypothyroidism has been associated with reduced folate absorption, while hyperthyroidism may increase folate utilization, potentially leading to deficiency.
- Good dietary sources of folate include leafy greens, legumes, and fortified grains.
Recommended Folate Intake
- The recommended daily intake of folate for adults is 400-800 mcg, which can be achieved through diet or supplementation [ 1 ].
- Folate status can be assessed by measuring levels of folate in serum/plasma or red blood cells, with serum folate levels should be 10 nmol/L and red blood cell folate 340 nmol/L [ 1 ].
Interconnection between Folate and Thyroid Hormones
- Thyroid hormones also influence folate metabolism, with hypothyroidism potentially reducing folate absorption and utilization.
- Addressing nutritional status, including folate levels, should be part of comprehensive thyroid management, particularly for patients with autoimmune thyroid conditions like Hashimoto's thyroiditis [ 1 ].
From the Research
Connection between Folate and Thyroid Function
- The relationship between folate and thyroid function is not extensively discussed in the provided studies, with the exception of one study that explores the metabolic relationship between thyroid stimulating hormone (TSH), folic acid, and B12 in the general population 2.
- According to this study, a positive, significant trend towards increased values of folic acid could be observed across the spectrum of TSH values suggestive for hypo- and hyperthyroidism, but the prevalence of subjects with folic acid or B12 deficiency did not differ significantly among the subgroups of subjects 2.
- The study also found that folic acid, but not B12, was associated with TSH levels in multivariable linear regression analysis, suggesting a potential link between folate and thyroid function 2.
- However, the study concludes that routine screening for either B12 or folic acid deficiency in subjects with subclinical disturbances of thyroid function may not be necessary, although it may still be useful in patients with overt thyroid dysfunction 2.
- The other studies provided focus on the diagnosis, treatment, and management of hypothyroidism, but do not discuss the connection between folate and thyroid function 3, 4, 5, 6.