Midlife Vitamin D Levels Linked to Later Tau-PET Deposition

 I just exited midlife at age 70, so my stuff is already baked in. But then I have way more than 16 years to go, so maybe still time.

Midlife Vitamin D Levels Linked to Later Tau-PET Deposition

 Higher circulating vitamin D levels in early midlife are associated with lower tau deposition on brain positron emission tomography (PET) imaging in later midlife among adults without dementia, according to a study published in Neurology Open Access. In a prospective cohort study of adults without dementia from the Framingham Heart Study Generation 3 cohort, researchers evaluated whether serum 25-hydroxyvitamin D measured in early midlife is associated with later tau and amyloid burden on brain PET imaging.Serum 25-hydroxyvitamin D levels were assessed at examination cycle 1 between 2002 and 2005. Participants subsequently underwent amyloid PET and/or tau PET imaging between 2016 and 2019. [H]igher vitamin D levels in midlife may offer protection against pathologic tau deposition in the brain, while low vitamin D may represent a potentially modifiable risk factor for healthy middle-aged individuals seeking to reduce dementia risk. A total of 793 participants were included, of whom 53% were women, and the mean [SD] age was 39 [8] years. Of the participants, 424 underwent amyloid PET imaging, and 369 underwent tau PET. The mean (SD) interval between vitamin D measurement and PET imaging was 16.2 (2.4) years. Outcomes included global and composite tau-PET burden and amyloid-PET burden. In fully adjusted models, higher serum 25-hydroxyvitamin D levels were associated with lower global tau-PET burden (β=−0.022; 95% CI, −0.040 to −0.004;P=.010) and lower composite tau-PET burden (β=−0.023; 95% CI, −0.043 to −0.003;P=.016). In contrast, serum 25-hydroxyvitamin D levels were not associated with amyloid-PET burden (β=0.001; 95% CI, −0.024 to 0.024;P=.987). When analyzed using a clinical cutoff (<30 vs ≥30 ng/mL), serum 25-hydroxyvitamin D levels were not significantly associated with tau or amyloid PET outcomes in fully adjusted models. Baseline mean (SD) serum 25-hydroxyvitamin D level was 38 (15) ng/mL, with 34% of participants below 30 ng/mL. Sensitivity analyses excluding individuals taking vitamin D supplements yielded similar findings, with persistent associations between higher serum 25-hydroxyvitamin D and lower tau burden. Study limitations include a lack of repeated vitamin D measurements over time, and the long interval between vitamin D assessment and PET imaging, which may introduce exposure misclassification. This study suggests that higher vitamin D levels in midlife may offer protection against pathologic tau deposition in the brain, while low vitamin D may represent a potentially modifiable risk factor for healthy middle-aged individuals seeking to reduce dementia risk,” concluded the authors.