{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T20:32:46Z","timestamp":1790195566644,"version":"4.1.0"},"reference-count":41,"publisher":"BMJ","issue":"8","license":[{"start":{"date-parts":[[2020,8,19]],"date-time":"2020-08-19T00:00:00Z","timestamp":1597795200000},"content-version":"unspecified","delay-in-days":18,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2020,5,30]]},"published-print":{"date-parts":[[2020,8]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>\n                      To compare the effectiveness of oral versus intramuscular (IM) vitamin B\n                      <jats:sub>12<\/jats:sub>\n                      (VB12) in patients aged \u226565 years with VB12 deficiency.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Pragmatic, randomised, non-inferiority, multicentre trial in 22 primary healthcare centres in Madrid (Spain).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>283 patients \u226565 years with VB12 deficiency were randomly assigned to oral (n=140) or IM (n=143) treatment arm.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Interventions<\/jats:title>\n                    <jats:p>The IM arm received 1 mg VB12 on alternate days in weeks 1\u20132, 1 mg\/week in weeks 3\u20138 and 1 mg\/month in weeks 9\u201352. The oral arm received 1 mg\/day in weeks 1\u20138 and 1 mg\/week in weeks 9\u201352.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Main outcomes<\/jats:title>\n                    <jats:p>Serum VB12 concentration normalisation (\u2265211 pg\/mL) at 8, 26 and 52 weeks. Non-inferiority would be declared if the difference between arms is 10% or less. Secondary outcomes included symptoms, adverse events, adherence to treatment, quality of life, patient preferences and satisfaction.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The follow-up period (52 weeks) was completed by 229 patients (80.9%). At week 8, the percentage of patients in each arm who achieved normal B\n                      <jats:sub>12<\/jats:sub>\n                      levels was well above 90%; the differences in this percentage between the oral and IM arm were \u22120.7% (133 out of 135 vs 129 out of 130; 95% CI: \u22123.2 to 1.8; p&gt;0.999) by per-protocol (PPT) analysis and 4.8% (133 out of 140 vs 129 out of 143; 95% CI: \u22121.3 to 10.9; p=0.124) by intention-to-treat (ITT) analysis. At week 52, the percentage of patients who achieved normal B\n                      <jats:sub>12<\/jats:sub>\n                      levels was 73.6% in the oral arm and 80.4% in the IM arm; these differences were \u22126.3% (103 out of 112 vs 115 out of 117; 95% CI: \u221211.9 to \u22120.1; p=0.025) and \u22126.8% (103 out of 140 vs 115 out of 143; 95% CI: \u221216.6 to 2.9; p=0.171), respectively. Factors affecting the success rate at week 52 were age, OR=0.95 (95% CI: 0.91 to 0.99) and having reached VB12 levels \u2265281 pg\/mL at week 8, OR=8.1 (95% CI: 2.4 to 27.3). Under a Bayesian framework, non-inferiority probabilities (\u0394&gt;\u221210%) at week 52 were 0.036 (PPT) and 0.060 (ITT). Quality of life and adverse effects were comparable across groups. 83.4% of patients preferred the oral route.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Oral administration was no less effective than IM administration at 8 weeks. Although differences were found between administration routes at week 52, the probability that the differences were below the non-inferiority threshold was very low.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration numbers<\/jats:title>\n                    <jats:p>NCT 01476007; EUDRACT (2010-024129-20).<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2019-033687","type":"journal-article","created":{"date-parts":[[2020,8,20]],"date-time":"2020-08-20T12:55:31Z","timestamp":1597928131000},"page":"e033687","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":52,"title":["Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care: a pragmatic, randomised, non-inferiority clinical trial (OB12)"],"prefix":"10.1136","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8791-8030","authenticated-orcid":false,"given":"Teresa","family":"Sanz-Cuesta","sequence":"first","affiliation":[{"name":"Research Unit. 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