Criticism for The American Society of Endocrinology's Recommendation Against Screening for Vitamin - D (June 2024)

Take Home Critique

Routine testing for vitamin D is still likely relevant as an individualised approach to care. While there is no data showing routine vitamin d population based screening is effective at improving morbidity/mortaity associated with vitaimn d deficiency, there is also no data showing it is ineffective. Certainly, have a discussion with your patient about the limited knowledge of the value for general screening, but there are numerous cases where routine screening has revealed excess or deficient vitamin D despite the individual taking the RDI of vitamin D through supplementation.

Background

The article by the Vitamin D and Health Outcomes Panel evaluates the benefits and drawbacks of routine vitamin D testing by analysing systematic reviews and meta-analyses of randomized controlled trials. It concludes that there is insufficient evidence to support routine vitamin D testing for the general population, advocating instead for empiric supplementation in specific high-risk groups. The panel highlights methodological limitations in the existing studies and suggests that future research should focus on populations with low baseline 25(OH)D levels to better understand the potential benefits of testing.

Methods/Results

The Vitamin D and Health Outcomes Panel employed a systematic review approach, prioritizing 14 clinically relevant questions to guide their recommendations. They focused on meta-analyses of randomized controlled trials (RCTs) to evaluate the effects of vitamin D supplementation on health outcomes. The panel excluded observational studies and Mendelian randomization studies, instead emphasizing high-quality RCTs. They also noted a significant limitation in the available RCTs, which often did not target populations with low baseline 25(OH)D levels and allowed participants to continue their usual vitamin D supplementation.

The results of the study indicated that there is insufficient evidence to support routine vitamin D testing for the general population. The panel found that existing RCTs did not consistently demonstrate significant health benefits from vitamin D supplementation across a range of outcomes. As a result, they recommended empiric vitamin D supplementation for specific high-risk groups rather than routine testing. The study highlighted the need for future research focusing on individuals with low baseline 25(OH)D levels to better understand the potential benefits of routine vitamin D testing.

Detailed Critique

Empiric Supplementation vs. Targeted Testing:

• The     panel suggests empiric vitamin D supplementation for certain groups without advocating for routine 25(OH)D testing. However, without testing, there is no way to ascertain whether supplementation is necessary or adequate, potentially leading to over- or under-supplementation. Routine testing could provide a more precise approach, ensuring individuals receive the appropriate dosage based on their specific needs.

Lack of Evidence for Routine Testing:

• The conclusion that there is no clear evidence to support routine 25(OH)D testing overlooks the potential preventive health benefits of identifying  and correcting deficiencies early. While large-scale RCTs may not have provided definitive evidence, the absence of evidence is not evidence of absence. Routine testing could help identify at-risk individuals who might not be captured through empiric supplementation alone.

Health Equity Considerations:

• The article mentions that empiric supplementation is considered inexpensive  and feasible, but it does not fully address how routine testing could  impact health equity. Routine testing could help ensure that vulnerable     populations, who might have higher rates of vitamin D deficiency due to factors like limited sun exposure or dietary intake, receive appropriate supplementation. This targeted approach could enhance health equity by     addressing disparities in vitamin D status.

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