The following is a summary of “Effect of Vitamin D Supplementation on Muscle Function in Patients With I131-Induced Hypothyroidism: A Pilot Randomized Trial,” published in the June 2024 issue of Endocrinology by Maneewan, et al.
Data on the impact of vitamin D supplements on patients with I131-induced hypothyroidism are limited. For a study, researchers sought to investigate the effects of vitamin D supplements on muscle function as the primary outcome and observe secondary outcomes, including body composition, insulin resistance, and quality of life (QOL) in these patients.
In the pilot randomized placebo-controlled trial, patients with I131-induced hypothyroidism receiving a stable dose of levothyroxine were enrolled and randomly assigned to receive either oral vitamin D (20,000 IU weekly) or placebo for 24 weeks. Baseline biochemical values, body composition, handgrip strength, the 5 times sit-to-stand test (5TSTS), homeostatic model assessment for insulin resistance (HOMA-IR), and QOL were assessed before the intervention and at 3 and 6 months. Mixed model regression analysis was used to compare group outcomes, with significance set at P < .05.
Each group comprised 20 participants. The time taken for the 5TSTS in the vitamin D group was significantly lower than in the placebo group at 3 months (P = .032) and 6 months (P = .006). However, other outcomes, including handgrip strength, body composition, HOMA-IR, and QOL, did not significantly differ between the two groups.
Supplementation with vitamin D2 at 20,000 IU per week for 24 weeks was associated with improved performance in the 5TSTS in patients with I131-induced hypothyroidism.