Table A1. Systematic Reviews of Treatment with B12 for Cognitive Function.
| Author, Year | Question (Sources Searched/Dates) | Studies Where B12 was Part of Treatment Arm | Study Included in this EBA? | Vitamin B12 Deficient? | Cognitive Impairment or Dementia? | Duration of Study (Months) | Overall Conclusion |
|---|---|---|---|---|---|---|---|
| Ford and Almeida, 2012 (44) | What is the efficacy of treatment with vitamins B12, B6, or folate in slowing cognitive decline among older adults with and without cognitive impairment? (PubMed, PsychINFO, Embase, Cochrane/to 2011) | Aisen et al, 2008 (51) | No | No | Yes (mild to moderate AD) | 18 | No difference in cognitive function whether receiving vitamin B12 supplementation or not |
| Clarke et al, 2003 (59) | No | No | Yes (mild to moderate dementia) | 3 | |||
| De Jager et al, 2012 (48) | No | No | Yes (mild cognitive impairment) | 24 | |||
| Kwok et al, 2011 (49) | No | No | Yes (mild to moderate AD or vascular dementia) | 24 | |||
| Garcia et al, 2004 (57) | No | No | No | 6 | |||
| Hvas et al, 2004 (58) | No | Likely (increased MMA implies low B12) | Mixed (1/3 cognitive impairment) | 3 | |||
| Eussen et al, 2006 (53) | No | Yes (100–200 pmol/L) | Mixed (40% mild-moderate cognitive impairment); results not stratified for patients with cognitive impairment | 6 | |||
| Ford et al, 2010 (50) | No | Not reported | Unclear | 24 | |||
| Kang et al, 2008 (52) | No | Not reported | Not reported at baseline | 60 | |||
| Seal et al, 2002 (61) | No | Yes (100–150 pmol/L) | Mixed (1/3 cognitive impairment); results not stratified for patients with cognitive impairment | 1 | |||
| Lewerin et al, 2005 (55) | No | No | Unclear | 4 | |||
| McMahon et al, 2006 (54) | No | Likely (high Hcy implies low B12) | No | 24 | |||
| Stott et al, 2005 (56) | No | No | Mixed (mild or moderate cognitive impairment included) | 12 | |||
| Jia et al, 2008 (45) | What is effect of nutrient supplementation on cognitive function in people aged ≥ 65 years? (MEDLINE, Embase/ to 2006) | De la Fourniere et al, 1997 (63) | No (full study in French, N = 11) | Yes (< 178 pmol/L) | Yes (all AD) | Not reported | No difference in cognitive function whether receiving vitamin B12 supplementation or not |
| Kwok et al, 1998 (62) | No | Yes (< 120 pmol/L) | Mixed (20% with dementia); results not stratified for patients with dementia | 4 | |||
| Bryan et al, 2002 (60) | No | Not reported | No | 1 | |||
| Seal et al, 2002 (61) | No | Yes (100–150 pmol/L) | Mixed (1/3 cognitive impairment); results not stratified for patients with cognitive impairment | 1 | |||
| Clarke et al, 2003 (59) | No | No | Yes (mild to moderate dementia) | 3 | |||
| Lewerin et al, 2005 (55) | No | No | Unclear | 4 | |||
| Stott et al, 2005 (56) | No | No | Mixed (mild or moderate cognitive impairment included) | 12 | |||
| Eussen et al, 2006 (53) | No | Yes (100–200 pmol/L) | Mixed (40% mild to moderate cognitive impairment); results not stratified for patients with cognitive impairment | 6 | |||
| McMahon et al, 2006 (54) | No | Likely (high Hcy implies low B12) | No | 24 | |||
| Balk et al, 2007 (46) | Does supplementation with vitamins B6, B12, and folic acid prevent or decrease progression of neurologic changes associated with dementia? (MEDLINE, Commonwealth Agricultural Bureau/to 2005) | Hvas et al, 2004 (58) | No | Likely (increased MMA implies low B12) | Mixed (1/3 cognitive impairment) | 3 | No difference in cognitive function whether receiving vitamin B12 supplementation or not |
| Eussen et al, 2006 (53) | No | Yes (100–200 pmol/L) | Mixed (40% mild-moderate cognitive impairment); results not stratified for patients with cognitive impairment | 6 | |||
| Bryan et al, 2002 (60) | No | Not reported | No | 1 | |||
| Seal et al, 2002 (61) | No | Yes (100–150 pmol/L) | Mixed (1/3 cognitive impairment); results not stratified for patients with cognitive impairment | 1 | |||
| Kwok et al, 1998 (62) | No | Yes (< 120 pmol/L) | Mixed (20% with dementia); results not stratified for patients with dementia | 3 | |||
| Kral et al, 1970 (64) | No (outdated) | N/A | N/A | N/A | |||
| Malouf and Areosa, 2003 (Cochrane Review) (47) | What is effect of vitamin B12 supplementation on cognitive function of demented and elderly healthy people in terms of preventing the onset or progression of cognitive impairment? (MEDLINE, Embase, Cochrane/to 2006) | Hvas et al, 2004 (58) | No | Likely (increased MMA implies low B12) | Mixed (1/3 cognitive impairment) | 3 | No difference in cognitive function whether receiving vitamin B12 supplementation or not |
| Seal et al, 2002 (61) | No | Yes (100–150 pmol/L) | Mixed (1/3 cognitive impairment); results not stratified for patients with cognitive impairment | 1 | |||
| De la Fourniere et al, 1997 (63) | No (full study in French, N = 11) | Yes (< 178 pmol/L) | Yes (all AD) | Not reported |
Abbreviations: AD, Alzheimer disease; EBA, evidence-based analysis; Hcy, homocysteine; MMA, methylmalonic acid.