Folate for Cognitive Elderly
Verdict: Published with Warning
Across 6 PubMed studies, the evidence for Folate in Cognitive Elderly grades Tier C — weak evidence. Effective, but with safety or population caveats.
C 🟠 C Weak Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.47
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
83%
Highly consistent evidence
Evidence level
E1
Cochrane high-quality SR/MA
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.472
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (2 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (6)L2 · primary research & systematic reviews
Folic acid with or without vitamin B12 for the prevention and treatment of healthy elderly and demented people
Finding: Across 8 RCTs (4 in healthy elderly, 4 in cognitive impairment/dementia) there was no consistent evidence that folic acid, with or without vitamin B12, benefits cognitive function in unselected older people, although in one high-homocysteine trial folate improved global function (WMD 0.05, 95% CI 0.004-0.096, P=0.033) and memory (WMD 0.14, 95% CI 0.04-0.24, P=0.006).
View on PubMed A Comparative Study Evaluating the Effectiveness of Folate-Based B Vitamin Intervention on Cognitive Function of Older Adults under Mandatory Folic Acid Fortification Policy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Finding: Pooled across 23 meta-analyzed RCTs the overall benefit was small (SMD 0.18, 95% CI 0.09-0.28, p=0.0001), but it was driven entirely by non-fortification regions (SMD 0.27, 95% CI 0.13-0.40, p=0.0002) and was null where folic acid fortification is mandatory (SMD 0.03, 95% CI -0.06-0.13, p=0.45).
View on PubMed The preventive efficacy of vitamin B supplements on the cognitive decline of elderly adults: a systematic review and meta-analysis
Finding: Across 21 RCTs B-vitamin supplementation improved global cognition (SMD 0.36, 95% CI 0.18-0.54, P<0.01) and lowered homocysteine (MD -4.59, 95% CI -5.51 to -3.67, P<0.01), but had no significant effect on episodic memory (SMD 0.10, 95% CI -0.04-0.25, P=0.16) or executive function (SMD -0.21, 95% CI -0.49-0.06, P=0.13).
View on PubMed Effect of 3-year folic acid supplementation on cognitive function in older adults in the FACIT trial: a randomised, double blind, controlled trial
Finding: In adults aged 50-70 with elevated homocysteine and normal B12 (non-fortified Netherlands), 800 ug/day folic acid for 3 years significantly improved memory (Z-score difference 0.132, 95% CI 0.032-0.233) and information processing speed (0.087, 95% CI 0.016-0.158), with sensorimotor speed borderline (0.064, 95% CI -0.001-0.129).
View on PubMed Effects of folic acid supplementation on cognitive function and inflammation in elderly patients with mild cognitive impairment: A systematic review and meta-analysis of randomized controlled trials
Finding: Across 7 RCTs (n=1102) folic acid improved some cognitive subtests in MCI (e.g. Block Design SMD 0.26, 95% CI 0.03-0.49; Information favoring folate) and reduced homocysteine and inflammatory cytokines, but other domains (Arithmetic, Digit Span, Picture Arrangement) showed no significant effect and several reported effect sizes in the abstract are internally inconsistent.
View on PubMed Efficacy of Vitamins on Cognitive Function of Non-Demented People: A Systematic Review and Meta-Analysis
Finding: Across 23 B-vitamin RCTs, taking B vitamins for over 3 months was beneficial for global cognition (SMD -0.18, 95% CI -0.30 to -0.06) and episodic memory (SMD -0.09, 95% CI -0.15 to -0.04), but folate was pooled with B6/B12 and no folate-specific effect size was reported.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Supportive
Health claims relating folate to risk of neural tube defects may be made on the label or in labeling of foods, including dietary supplements, provided that the requirements in this section are met. source↗
L4b EU EFSA
Supportive
L4c UK NHS
Neutral
It's recommended that all women who could get pregnant should take a 400 microgram folic acid supplement daily before pregnancy and until they're 12 weeks pregnant. source↗
L4d TW TFDA / 衛福部
Supportive
孕期缺乏葉酸，會增加胎兒腦及脊髓先天性神經管缺陷的風險。育齡婦女及準備懷孕婦女可在準備階段每日攝取400微克，懷孕期間每日攝取600微克。 source↗
L4e WHO
Neutral
Current evidence suggests that folic acid supplementation in the periconceptional period, either alone or in combination with other vitamins and minerals, can prevent neural tube defects. source↗
L5a NIH Office of Dietary Supplements
Supportive
L5b Mayo Clinic
Cautious
There's no conclusive evidence that folic acid supplements improve cognitive function in older adults or in people with Alzheimer's disease or other types of dementia. However, checking your folic acid levels may be a reasonable step if you're at high risk of developing dementia or have already experienced some cognitive decline. source↗
L5c Cleveland Clinic
Supportive
Taking folic acid supplements may improve memory and thinking skills in older adults who experience faster-than-normal decline. One study also suggested a possible link between folate deficiency and an increased risk of Alzheimer's disease. Low levels of folate slightly increase the risk for Alzheimer's disease. The benefits of folate can best be explained as lowering inflammation in the brain. source↗
L5d Harvard Health
Cautious
B vitamins (folic acid, B6, and B12) ... For now, you can cross most of these products off your shopping list for lack of evidence. source↗
L5e Specialty Society (condition-mapped)
Cautious
Monitoring B12 and folate levels is important in order to avoid unfavorable conditions, even for those elderly people who are quite healthy in terms of cognition. Low levels of either of these two vitamins were related to an increased Alzheimer's disease risk. source↗