The 2024 Endocrine Society Guideline on Vitamin D: Comprehensive Summary and Critical Appraisal

Background/Objectives: An Endocrine Society Clinical Practice Guideline on vitamin D was published in 2024. Its main objective was the use of vitamin D to lower the risk of disease in individuals without established indications for vitamin D treatment or 25-hydroxavitamin D (25(OH)D) testing. The methodology followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) and the Evidence-to-Decision (EtD) framework. Evidence from randomized controlled trials (RCTs) retrieved by a systematic review was prioritized to inform this guideline. It was concluded that vitamin D supplementation reduces rickets and respiratory tract infections in children, mortality in individuals aged 75 years or older, pregnancy complications (outcomes), and progression of prediabetes to diabetes mellitus. Consequently, empiric vitamin D supplementation was recommended for individuals aged 1 to 18 years and ≥75 years, pregnant women, and individuals with prediabetes. Empiric vitamin D supplementation is defined as a vitamin D intake that exceeds the Dietary Reference Intakes (DRIs) and is implemented without 25(OH)D testing. Methods: This article provides a comprehensive guideline summary and critical appraisal based on a narrative review on scientific publications regarding that guideline. Results: Several publications discussed the 2024 Endocrine Society Clinical Practice Guideline on vitamin D. The main criticisms and discussion relate to unclear vitamin D dosages, guideline applicability to certain populations including controversy with previous vitamin D guidelines, and the implications of 25(OH)D testing. Conclusions: The 2024 Endocrine Society Clinical Practice Guideline on vitamin D followed a rigorous methodological approach with high quality standards but it leaves many open questions and uncertainties warranting clarification.