0
0
The Endocrine Society has issued new guidelines recommending that vitamin D supplementation be limited to specific risk groups and advising against routine 25-hydroxyvitamin D [25(OH)D] testing in healthy individuals. These guidelines, presented on June 3, 2024, at the Endocrine Society annual meeting and published in the Journal of Clinical Endocrinology and Metabolism, emphasize evidence-based recommendations for vitamin D intake.
Targeted Supplementation for Specific Groups
The guidelines identify several groups that may benefit from increased vitamin D supplementation:
- Children aged 1-18 years: To prevent rickets and potentially reduce the risk of respiratory tract infections.
- Pregnant individuals: To lower the risk of maternal, fetal, or neonatal complications.
- Adults older than 75 years: To reduce mortality risk.
- Adults with prediabetes: To lower the risk of developing type 2 diabetes.
For these groups, daily vitamin D supplementation exceeding the 2011 recommendations by the National Academy of Medicine (NAM)—600 IU/day for those aged 1-70 years and 800 IU/day for those over 70 years—is advised. However, the optimal dose remains undetermined, with the guidelines providing dose ranges used in supporting clinical trials.
General Population Guidelines
For most healthier adults under 75, the guidelines recommend adhering to the NAM’s daily intake levels and advise against testing for blood vitamin D levels, even in those with obesity or darker complexions. According to Dr. Anastassios G. Pittas, a guideline author and professor of medicine at Tufts University, these recommendations apply to otherwise healthy individuals without specific indications for vitamin D, such as established osteoporosis.
Need for Further Research
The guideline panel, chaired by Dr. Marie B. Demay of Harvard Medical School, highlighted the lack of randomized clinical trial evidence to address many crucial questions regarding optimal vitamin D levels and intake for disease prevention. “What we really need are large scale clinical trials and biomarkers so we can predict disease outcomes before they happen,” Demay stated.
Clinical Practice Implications
Dr. Clifford J. Rosen, session moderator and senior scientist at Maine Medical Center Research Institute, supported the recommendation against routine vitamin D screening. “When clinicians measure vitamin D, they’re forced to make decisions based on unclear thresholds. We have no data showing that screening improves quality of life, making it probably not worthwhile in any age group.”
Criticisms and Limitations
Despite its strengths, the document faced criticism for its limited scope, focusing only on healthy individuals. Dr. Simeon I. Taylor from the University of Maryland expressed disappointment over the lack of guidance for managing vitamin D status in patients with chronic diseases such as kidney disease or inflammatory bowel disease. He also suggested that alternative testing strategies might offer better insights into vitamin D status, taking into account individual variations in vitamin D binding protein levels.
Race, Ethnicity, and Vitamin D
The guidelines address the complexities of skin pigmentation and race in vitamin D metabolism, noting the absence of randomized trials specifically assessing outcomes based on skin pigmentation. The panel underscored the importance of distinguishing between biological skin pigmentation and socially determined race and ethnicity constructs to enhance scientific rigor.
Conclusion
While the new guidelines provide a structured approach to vitamin D supplementation and testing, they underscore the need for further research to refine these recommendations and address gaps in clinical evidence. The Endocrine Society’s guidelines represent a step forward in tailoring vitamin D intake to specific populations while cautioning against unnecessary testing and supplementation in the general population.
