Comparative Efficacy of NASO B12 Versus Sublingual Methylcobalamin in Treating Vitamin B12 Deficiency: A Randomised Open-Label Clinical Trial

Background: Vitamin B12 is crucial for DNA synthesis, haematological and neurological functions. Conventional Vitamin B12 supplementation methods, including intramuscular and oral routes, have limitations. The intramuscular injections are painful, and their dosing schedule is inconvenient. Methylcobalamin oral tablets lack consistent and predictable absorption of vitamin B12. NASO B12 (Methylcobalamin nasal spray) offers a painless and novel alternative; however, there is no data to compare it directly with Methylcobalamin sublingual tablets. Objective: To evaluate the efficacy of NASO B12 (Methylcobalamin 250 mcg/spray) versus Methylcobalamin sublingual tablet (1500 mcg) in Vitamin B12-deficient patients. Methods: In a randomised, open-label study conducted at a primary healthcare facility, 30 patients with confirmed Vitamin B12 deficiency (<200 pg/ml) were administered either NASO B12 (500 mcg every alternate day) or Methylcobalamin sublingual tablet available on the market (1500 mcg every alternate day). Vitamin B12 levels in the blood were measured at baseline, 30 minutes after administration of the first dose, and on Day 6 (a total of three doses of each product). Results: NASO B12 achieved significantly higher Vitamin B12 levels in the blood, 30 minutes after administration of first dose (1397.3 ± 369.03 pg/ml vs. 197.9 ± 29.7 pg/ml, p < 0.001) and on Day 6 (839.5 ± 163.02 pg/ml vs. 267.6 ± 37.61 pg/ml, p < 0.001). NASO B12 showed a greater mean increase in serum Vitamin B12 levels from baseline than the sublingual tablet at both 30 minutes (1,219.7 vs. 24.7 pg/mL) and Day 6 (661.8 vs. 94.4 pg/mL). All patients in the NASO B12 group achieved a Vitamin B12 ≥ 400 pg/ml level as recommended by the American Academy of Family Physicians (AAFP), whereas none of the patients in the Methylcobalamin sublingual tablet group achieved the same. Both treatments were well tolerated. Conclusion: NASO B12 exhibited rapid, predictable and superior absorption, along with sustained therapeutic Vitamin B12 levels (>400 pg/ml), as compared to the Methylcobalamin sublingual tablet. This highlights the potential of NASO B12 as an effective and patient-friendly alternative for the rapid and assured correction of Vitamin B12 deficiency.