The effect of vitamin B12 and folic acid supplementation on routine haematological parameters in older people: an individual participant data meta-analysis

• Published in: European journal of clinical nutrition 2018-06, Vol.72 (6), p.785-795
• Main Authors: Smelt, Antonia FH, Gussekloo, Jacobijn, Bermingham, Lynette W, Allen, Elizabeth, Dangour, Alan D, Eussen, Simone JPM, Favrat, Bernard, De Groot, Lisette CPGM, Kok, Frans J, Kwok, Timothy, Mangoni, Arduino A, Ntaios, George, Van De Rest, Ondine, Seal, Eric, Vaucher, Paul, Verhoef, Petra, Stijnen, Theo, Den Elzen, Wendy PJ
• Format: Article
• Language: English
• Subjects: 692/308/174; 692/308/2778; Acids; Afdeling Humane voeding; Anemia; Chair Nutrition and Health over the Lifecourse; Clinical Nutrition; Clinical trials; Communities; Cyanocobalamin; Data analysis; Data processing; Epidemiology; Folic acid; Geriatrics; Global Nutrition; Hematology; Hemoglobin; HNE Nutrition and Health over the Lifecourse; HNE Voeding en Gezondheid in de Levenscyclus; Human Nutrition; Human Nutrition & Health; Human Nutrition (HNE); Humane Voeding; Humane Voeding & Gezondheid; Internal Medicine; Low concentrations; Medicine; Medicine & Public Health; Meta-analysis; Metabolic Diseases; Older people; Parameters; Patients; Public Health; Review Article; Subgroups; Supplements; Systematic review; Vitamin B; Vitamin B12; VLAG; Wereldvoeding
• ISSN: 0954-3007; 1476-5640
• DOI: 10.1038/s41430-018-0118-x

Background/objectives Low vitamin B12 and folate levels in community-dwelling older people are usually corrected with supplements. However, the effect of this supplementation on haematological parameters in older persons is not known. Therefore, we executed a systematic review and individual participant data meta-analysis of randomised placebo-controlled trials (RCTs). Subjects/methods We performed a systematic search in PubMed, EMBASE, Web of Science, Cochrane and CENTRAL for RCTs published between January 1950 and April 2016, where community-dwelling elderly (60+ years) who were treated with vitamin B12 or folic acid or placebo. The presence of anaemia was not required. We analysed the data on haematological parameters with a two-stage IPD meta-analysis. Results We found 494 full papers covering 14 studies. Data were shared by the authors of four RCTs comparing vitamin B12 with placebo ( n  = 343) and of three RCTs comparing folic acid with placebo ( n  = 929). We found no effect of vitamin B12 supplementation on haemoglobin (change 0.00 g/dL, 95% CI: −0.19;0.18), and no effect of folic acid supplementation (change −0.09 g/dL, 95% CI: −0.19;0.01). The effects of supplementation on other haematological parameters were similar. The effects did not differ by sex or by age group. Also, no effect was found in a subgroup of patients with anaemia and a subgroup of patients who were treated >4 weeks. Conclusions Evidence on the effects of supplementation of low concentrations of vitamin B12 and folate on haematological parameters in community-dwelling older people is inconclusive. Further research is needed before firm recommendations can be made concerning the supplementation of vitamin B12 and folate.