Abstract Topic: 28. Enzymopathies, membranopathies and other anemias
Background: Vitamin B12 (VB12) and folic acid are essential components involved in the synthesis of DNA. Vitamin B12 deficiency mainly leads to haematological, neuropsychiatric, or cardiovascular manifestations. The prevalence of symptomatic and asymptomatic vitamin B12 deficiency is 47% in North India whereas the prevalence of anemia with vitamin B12 deficiency is around 11.6% as per the literature.
In the haematology ward and OPD, most patients are thrombocytopenic and a few have bleeding disorders. Administration of intramuscular injection is usually not advisable due to the risk of hematoma formation at the local site and complications like an abscess. Hence the routine practice in most haematology wards is to use intravenous vitamin B12 injection instead of intramuscular. In the case of vitamin B12 daily intravenous or intramuscular injection, he needs to visit the hospital daily for 1 week which might be logistically difficult. Moreover, whether daily dosing of vitamin B12 is really needed has not been adequately studied. There are no definitive guidelines on the use of oral versus intravenous vitamin B12 (Vitamin B12) in anemia with vitamin B12 deficiency. It would be important to seek evidence for the most effective route for the treatment of these patients
Aims: To assess the response to oral versus intravenous vitamin B12 supplementation in anemia with vitamin B12 deficiency by the change in serum vitamin B12 level. The secondary objectives were a rise in the level of Hb and MCV along with cost analysis and resolution of signs and symptoms post-therapy.
Methods: This was a prospective, randomized, open-label, interventional study comparing oral versus weekly intravenous vitamin B12 replacement at a tertiary care center. Participants with anemia for age and gender with pre-therapy vitamin B12 levels below 250 picogram/ml were enrolled in the study from May 2020 to December 2021. Block randomization and allocation concealment was done using sequentially numbered, opaque sealed envelopes (SNOSE) and monitored by the central coordinator. Arm A had daily oral vitamin B12 and Arm B had weekly intravenous vitamin B12 given for over 4 weeks. The primary objective of the study was the evaluation of vitamin B12 levels at 5 weeks. Post-therapy improvement in signs and symptoms, hemoglobin and, MCV response were the secondary objectives.
Results: A total of 37 participants were enrolled in the study. The study group had predominantly females (64.8%) with a median age of 32 years (Q1-Q3,21 – 52). The most common presenting symptoms were easy fatiguability (48%), hair fall (37%), and parasthesia (19%). The pre-therapy mean vitamin B12 level in the oral and IV arms was 157 ± 66 picogram/ml and 173 ± 55 picogram/ml (p=0.59) respectively and the post-therapy mean vitamin B12 level was 870 ± 348 picogram/ml and 1273 ± 511 picogram/ml (p=0.02) respectively [Figure 1]. The mean change in vitamin B12 level was compared among both oral and weekly IV arms using an independent T-test. The mean change in the oral VB12 arm was 713 ± 372 picogram/ml and in the weekly IV arm was 1100 ± 535 picogram/ml. It was statistically significant in weekly IV arm with a p-value of 0.017. On comparison between the two arms, the weekly IV arm had a statistically significant mean change in vitamin B12 level than the oral arm. The baseline hemoglobin in oral and IV arms was 10.9 ± 1.3 gram/dl and 10.5 ± 2.1 gram/dl (p=0.5) respectively and the post-therapy Hb was 12.1 ± 1.3 gram/dl and 12.3 ± 1.1 gram/dl (p=0.7) respectively. The mean change in Hb was not significant on comparison between the two arms (p=0.65). No other parameters showed significant difference.
Conclusion:
Normalization of vitamin B12 level was seen with both oral and intravenous vitamin B12, however, the weekly intravenous supplementation showed a statistically significant increase in vitamin B12 level than daily oral supplementation. Oral vitamin B12 is more cost-effective and preferred by patients. Considering that the IV route provided a faster increase in vitamin B12 levels, it could be a better option in patients with severe vitamin B12 deficiency.
Figure 1: Shows study arms on X axis and mean post-therapy vitamin B12 levels on Y axis.
Keywords: Anemia