Longitudinal association between exposure to vitamin D supplementation and incident dementia – A study of dementia‐free older adults
Bibliographic record
Abstract
Abstract Background In the absence of clear disease‐modifying drugs for dementia, modifiable risk factors have been explored to slow disease progression. Vitamin D deficiency is a risk factor, associated with higher risk of dementia. However, the role of vitamin D supplementation has been a subject of debate. Here we explored longitudinal associations between vitamin D supplementation and incident dementia in dementia‐free older adults from the National Alzheimer’s Coordinating Center (NACC). Method All participants had normal cognition (NC) or mild cognitive impairment (MCI) at baseline. Exposure to vitamin D supplementation was based on the NACC A4 medication form. Three vitamin D formulations were considered: calcium‐vitamin D, cholecalciferol, and ergocalciferol. For the primary analysis, participants with baseline exposure to any supplement were considered D+, while those without any exposure in advance of dementia diagnosis were considered D‐. Kaplan‐Meier curves were generated to compare ten‐year dementia‐free survival between D+ and D‐ groups. Cox proportional hazards models were implemented to assess the risk of dementia across vitamin D exposure groups, adjusted for baseline age, sex, years of education, race, APOE‐e4 status, cognitive diagnosis, and depression. To distinguish the associations of various vitamin D formulations with risk of dementia, sensitivity analyses were conducted to independently examine the effect of each formulation (calcium‐vitamin D, cholecalciferol, ergocalciferol). Result The final sample consisted of 2836 D+ (mean age = 72.1; 68.4% female) and 5075 D‐ participants (mean age = 72; 45.1% female). MCI was more prevalent in D‐ vs D+ participants (35.7% vs 26.8%; p<0.001). Similarly, depression was more prevalent in D‐ vs D+ participants (6.9% vs. 4.3%, p<0.001). Across all three vitamin D formulations, exposure was associated with longer dementia‐free survival (p<0.001) and lower adjusted hazard ratio (HR) for incident dementia compared to no exposure (calcium‐vitamin D: HR = 0.56, 95%CI: 0.47‐0.67, p<0.001; cholecalciferol: HR = 0.72, 95%CI: 0.56‐0.91, p = 0.007; ergocalciferol: HR = 0.75, 95%CI: 0.63‐0.89, p<0.001) Conclusion Our findings demonstrate that while adjusting for demographic, cognitive, behavioral, and genetic factors, exposure to vitamin D supplementation (calcium‐vitamin D, cholecalciferol, or ergocalciferol) in dementia‐free older adults was associated with lower risk of dementia, implicating vitamin D as a potential agent for dementia prevention.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".