Published Aug 20, 2026 | 9:00 AM ⚊ Updated Aug 20, 2026 | 9:00 AM
Healthy ageing requires attention not only to disease management but also to nutritional well-being.
Synopsis: A Hyderabad study by ICMR-NIN found mild cognitive impairment in 36.4% of older adults, with vitamin D, B2 and B9 deficiencies significantly more common among them. The findings link micronutrient status with cognitive performance and neuronal biomarkers, but researchers caution that the cross-sectional study cannot establish causation.
A study conducted in Hyderabad tracked 184 adults aged 55 to 85 and found something that unsettles anyone counting down to retirement. Nearly four in 10 carried signs of mild cognitive impairment (MCI), a stage where memory slips but daily life still runs on autopilot. Vitamins sat at the centre of the pattern.
Researchers at the ICMR-National Institute of Nutrition (NIN) in Hyderabad, working with the Kamineni Academy of Medical Sciences and Research Centre, ran blood tests alongside cognitive screening between January 2024 and March 2025. They published their results in Nutrients on 24 July.
MCI was detected in 36.4% of participants. Among those with MCI, 72% were low on vitamin D. That figure fell to 48% among those without impairment. Vitamin B2 deficiency affected 63% of the MCI group, compared with 37% of the rest. Folate (B9) deficiency was at 11% of the MCI group, compared with just 2% elsewhere.
Blood levels of vitamins D, B1, B2, B6 and B9 all dropped further in the MCI group than in the comparison group.
The team also added deficiencies across six vitamins per person. Anyone lacking more than two vitamins landed in a high-burden bracket. That bracket held 39% of the MCI group, but only 19% of those without impairment.
“Healthy ageing requires attention not only to disease management but also to nutritional well-being,” said Dr Bharati Kulkarni, director of ICMR-NIN.
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The team didn’t stop at vitamins. They tested biomarkers tied to neuron damage, including beta-amyloid, total tau and neurofilament light chain (NfL). All three climbed in the MCI group.
Brain-derived neurotrophic factor (BDNF), a protein that guards neurons, dropped in the same group. Blood sugar markers (HbA1c) and systolic blood pressure climbed too, linking the findings to risk factors doctors already track.
Correlation tests then connected vitamin levels directly to cognition scores on the Montreal Cognitive Assessment (MoCA). Vitamin D scored a coefficient of 0.24, B6 hit 0.20, and B9 reached 0.22, each statistically significant. Vitamin D and B6 showed the strongest association with a lower probability of MCI after adjusting for age, sex, education, body mass index, blood sugar, blood pressure, and the neuronal markers.
For vitamin D, predicted MCI probability dropped from 0.94 at low blood levels to 0.20 at high levels. Vitamin B6 showed an even steeper swing, from 0.92 down to 0.04.
Individual vitamins struggled to separate the two groups with much precision on their own. Vitamin D alone produced an area under the curve (AUC) of 0.67 in receiver operating characteristic (ROC) analysis, a modest score.
Combinations changed that picture. Pairing vitamin B6 with vitamin D pushed the AUC to 0.73. Adding B12 lifted it to 0.76. A four-vitamin model built from B2, B6, B12 and D reached 0.78, the strongest performance in the study. Folding in B9 added nothing further.
Vitamin B2 correlated with BDNF and NfL specifically, hinting at links to neuron protection and injury. Vitamin B6 correlated with total tau. “Micronutrient status may influence early neurodegenerative processes underlying cognitive impairment,” the authors wrote.
Cognitive domains also split along vitamin lines. Participants short on B2 scored worse on naming, attention and language tasks. Those short on B9 struggled more with attention, delayed recall and orientation.
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Researchers split Hyderabad into four zones, east, west, north and south, and picked two wards from each zone through random sampling. Health camps in each ward gathered volunteers, who received an explanation of the study before agreeing to join.
Trained staff recorded height, weight, waist and hip measurements, plus blood pressure taken three times with five-minute gaps between readings. Well-preserved Blood samples were sent to the lab within four hours of collection, then split into portions for glucose testing, vitamin analysis and biomarker work.
Vitamins A and D went through liquid chromatography paired with ultraviolet detection. Vitamins B1, B2 and B6 ran through chromatography kits built for fluorescence detection. Folate and B12 were measured using an immunoanalyzer that uses chemiluminescence to bind and quantify each molecule. Neuronal biomarkers, including beta-amyloid, tau and NfL, went through enzyme-linked immunosorbent assay (ELISA) kits designed to catch even small traces of each protein.
Cognitive testing ran through the Telugu version of the MoCA, a tool validated across Indian languages. The test covers eight domains: visuospatial and executive function, naming, language, memory, delayed recall, attention, abstraction and orientation, scored out of 30 points.
Most studies use a MoCA score of 26 as the cut-off for flagging MCI, but the researchers chose 23 instead, following recent evidence that a score of 26 flags too many people who turn out fine. “A cut-off of 23 yields the best diagnostic accuracy,” the study noted, citing a systematic review that reached the same conclusion.
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Dr G. Bhanuprakash Reddy, who led the research team, called for more work before anyone treats this as a fix. “Further longitudinal studies and clinical trials were needed to establish whether improving nutritional status could prevent or slow cognitive decline,” he said.
The study captured a single snapshot in time rather than following people across years. It cannot prove that low vitamins cause cognitive decline, only that the two travel together. The researchers also flagged possible selection bias in how participants joined the study, plus a sample too small to split results reliably by gender.
From 1,020 volunteers screened at community health camps across Hyderabad’s four zones, 104 dropped out for taking multivitamins, 290 fell outside the study’s health criteria, and 342 declined blood draws. That left 184 participants, 116 men and 68 women.
“Healthy ageing requires attention not only to disease management but also to nutritional well-being,” the authors repeated in their conclusion, framing vitamin status as one lever among several that doctors and policymakers can pull.
Age separated the groups more than lifestyle did. Participants with MCI carried a median age of 67 years, against 63 years for those without impairment.
Diet leaned mixed rather than vegetarian in both groups, with 69% of the MCI group eating meat, eggs, or fish, compared with 56% in the comparison group. Living arrangements barely moved the needle: 4.5% of the MCI group lived alone, against 1.7% of the rest. Alcohol use and smoking showed no gap between groups at all.
That pattern led investigators away from lifestyle habits and toward the biology beneath them: blood sugar, blood pressure, and vitamin status.
India’s population is ageing fast, with the share of people over 65 climbing steadily. Estimates point to 7.5 possible million dementia cases by 2040. MCI sits as a checkpoint before that outcome, though not everyone who develops MCI goes on to dementia.
The researchers frame nutrition as one of the few levers that public health systems can actually pull, unlike genetic risk, which resists intervention. “Nutrition, blood sugar, blood pressure and cognitive checks could aid healthy ageing,” they noted, tying vitamin screening to the same toolkit doctors already use for diabetes and hypertension.
Vitamin D and the B-group vitamins carry known roles in the brain: energy production inside neurons, defence against oxidative damage, and construction of neurotransmitters that carry signals between cells. Folate and B12 also drive one-carbon metabolism, a chemical process that regulates DNA and manages homocysteine, an amino acid tied to vascular and neuron damage when it builds up.
It doesn’t prove cause and effect in the 184-person group. But it gives researchers a reason to keep testing the link in bigger, longer studies.
The authors called for larger studies that track people over years rather than months, so scientists can see whether vitamin deficiencies arrive before cognitive decline starts, or whether declining cognition itself changes how people eat and absorb nutrients.
They also wanted trials that test whether correcting deficiencies through diet or supplements can slow or block MCI, something this study cannot answer on its own.
For now, the take-away sits closer to a prompt than a prescription: blood tests for vitamin D, B2, B6, B9 and B12 could join blood sugar and blood pressure checks as part of routine screening for older adults, giving doctors an early signal before memory loss sets in.
“These findings may have important implications for public health approaches aimed at promoting healthy brain ageing through early nutritional interventions and risk-reduction strategies,” the authors concluded.
(Edited by Majnu Babu).
