Hypothyroidism has no significant correlation with vitamin deficiencies and usually does not require additional vitamin supplements, which can be obtained from a normal daily diet; it is the thyroid hormones that need to be supplemented. The pathogenesis of hypothyroidism is complex, with the most common cause being autoimmune injury, such as hypothyroidism due to Hashimoto’s thyroiditis and atrophic thyroiditis. Hypothyroidism does not usually result in vitamin deficiencies, and people with a normal diet can obtain their daily vitamin requirements from foods (e.g., fresh fruits and vegetables) without additional supplementation. Patients with irregular diets or absorption disorders should take additional vitamin supplements under medical supervision. Since hypothyroidism patients have low levels of thyroid hormones, exogenous supplementation of thyroid hormones is usually needed for replacement therapy, and the commonly used drug is levothyroxine, and the specific dosage should be instructed by a doctor.