A RANDOMIZED TRIAL OF SELENIUM-BIOFORTIFIED WHEAT CONSUMPTION ON THYROID FUNCTION AND MOOD IN SUBCLINICAL HYPOTHYROID ADULTS.

Background: Subclinical hypothyroidism is frequently associated with inadequate selenium status, which may impair thyroid hormone metabolism and influence mood regulation. Food-based strategies such as selenium-biofortified wheat offer a feasible approach to improving micronutrient intake without reliance on supplements. Objective: This study aimed to evaluate the effects of selenium-biofortified wheat consumption on thyroid function and mood outcomes in adults with subclinical hypothyroidism. Methods: A randomized controlled trial was conducted among adults with mildly elevated TSH and normal FT4 levels. Participants were assigned to consume either selenium-biofortified wheat or non-biofortified wheat for 12 weeks. Primary outcomes included serum selenium, TSH, FT4, and FT3. Secondary outcomes included depressive symptoms and state and trait anxiety scores. Measurements were obtained at baseline and week 12. Results: Serum selenium concentrations increased substantially in the intervention group, rising from 72.1 µg/L to 118.4 µg/L, compared with a modest increase in the control group. TSH levels decreased more markedly in the biofortified group (5.12 to 3.98 mIU/L) than in controls. Small but consistent improvements in FT4 and FT3 were observed only in the intervention group. Mood outcomes reflected similar patterns, with the biofortified group demonstrating greater reductions in depressive symptoms and anxiety scores than controls. No serious adverse events occurred, and adherence was high in both groups. Conclusion: Selenium-biofortified wheat enhanced selenium status, improved key thyroid biomarkers, and contributed to better mood outcomes in subclinical hypothyroid adults. These findings support the potential of food-based selenium delivery as a practical and sustainable strategy for improving thyroid-related and psychological health indicators.