Vitamin D supplementation resulted in thicker Brain Cortex – RCT June 2021

Vitamin D Intake and Brain Cortical Thickness in Community-Dwelling Overweight Older Adults: A Cross-Sectional Study

J Nutr. 2021 Jun 10;nxab168. doi: 10.1093/jn/nxab168
Sophie Lefèvre-Arbogast 1 2, Klodian Dhana 1 2, Neelum T Aggarwal 3, Shengwei Zhang 3, Puja Agarwal 2 3, Xiaoran Liu 1 2, Nancy Laranjo 4 5, Vincent Carey 4 5 6, Frank Sacks 7, Lisa L Barnes 3, Konstantinos Arfanakis 3 8 9

Background: Vitamin D is critical to brain health and a promising candidate to prevent cognitive decline and onset of Alzheimer disease (AD), although the underlying brain mechanisms are unclear.

Objectives: This study aimed to determine the association between vitamin D intake and brain cortical thickness in older adults.

Methods: This was a cross-sectional investigation of 263 cognitively unimpaired participants, aged 65 y and older, participating in the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) trial (an ongoing study testing the effects of a 3-y diet intervention on cognitive decline). Vitamin D intake, from diet and supplements, was ascertained from an FFQ. Linear regression analysis, adjusted for age, sex, race, education, income, cognitive and physical activities, and cardiovascular disease risk factors, was used to determine the association between vitamin D intake and cortical thickness of the whole brain, lobes, and AD signature.

Results: Total vitamin D intake was associated with cortical thickness of the temporal lobe and AD signature. Compared with individuals in the lowest quartile of total vitamin D intake [median: 140 international units (IU)/d], those in the highest quartile (median: 1439 IU/d) had a 0.038-mm (95% CI: 0.006, 0.069 mm) thicker temporal lobe and 0.041-mm (95% CI: 0.012, 0.070 mm) thicker AD signature. Most vitamin D intake was from supplements, and supplemental intake was also associated with cortical thickness.
Compared with those who used no supplement, individuals taking 800-1000 IU/d and >1000 IU/d of supplemental vitamin D had a 0.039-mm (95% CI: 0.013, 0.066 mm) and 0.047-mm (95% CI: 0.013, 0.081 mm) thicker temporal lobe and a 0.037-mm (95% CI: 0.013, 0.061 mm) and 0.046-mm (95% CI: 0.015, 0.077 mm) thicker AD signature, respectively. Dietary vitamin D was not related to brain cortical thickness in our sample.

Conclusions: In cognitively unimpaired older adults, total and supplemental vitamin D intakes were associated with cortical thickness in regions vulnerable to AD. This trial was registered at clinicaltrials.gov as NCT02817074

Detailed Description at Clinical Trials
Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND) is a Phase III randomized controlled trial designed to test the effects of a 3-year intervention of a hybrid of the Mediterranean and DASH diets, called MIND, on cognitive decline among 600 individuals 65+ years without cognitive impairment who are overweight and have suboptimal diets. The proposed MIND diet is a hybrid of the Mediterranean and DASH diets but with selected modifications based on the most compelling evidence in the diet-dementia field. The MIND diet has the same basic components of the DASH and Mediterranean diets, such as emphasis on natural plant-based foods and limited animal and high saturated fat foods, but uniquely specifies green leafy vegetables and berries as well as food component servings that reflect the nutrition-dementia evidence. The trial will employ a parallel group design comparing the effects on cognitive outcomes of the MIND intervention diet plus mild caloric restriction for weight loss to the control diet, usual diet with mild caloric restriction for weight loss. Biological effects of the MIND diet will be assessed by measurement of brain macro- and micro-structural integrity in 300 randomly selected participants. Other biochemical markers will be assessed in the entire cohort of 600 participants, including: plasma Abeta 42/Abeta 40, brain-derived neurotrophic factor (BDNF) and plasma markers of oxidative stress and inflammation. In addition, the trial will examine potential effect mediators and modifiers by a number of cardiovascular risk factors, AD biomarkers, and biological mechanisms. The proposed study has two clinical sites, one in Chicago (Rush University) and one in Boston (Harvard University), and centralized laboratories for data coordinating and analyses (Brigham & Women's Hospital), neuroimaging analyses (Rush University), and specialized laboratories for tissue biochemical analyses.