This Randomized, Clinical Trial Evaluates the Efficacy of Oral Versus Sublingual Vitamin B12 Supplementation in Correcting Early-onset Vitamin B12 Deficiency in Adult Patients Using Proton Pump Inhibitors (PPIs). The Primary Outcome is the Change in Serum Vitamin B12 Levels Over a 6-week

Sublingual Versus Oral Vitamin B12 for Acute Hypovitaminosis B12 Secondary to Proton Pump Inhibitors: A Prospective Randomized Study

Status

Not yet recruiting

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06966856

Enrollment

Registered

2025-05-13

Start date

2026-12-30

Completion date

2029-12-30

Last updated

2025-05-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hypovitaminosis b 12

Brief summary

This randomized, clinical trial evaluates the efficacy of oral versus sublingual vitamin B12 supplementation in correcting early-onset vitamin B12 deficiency in adult patients using proton pump inhibitors (PPIs). The primary outcome is the change in serum vitamin B12 levels over a 6-week treatment period. Secondary outcomes include changes in homocysteine levels, hemoglobin levels, and patient-reported satisfaction.

Interventions

DRUGCyanocobalamin 1000 Mcg Oral Tablet

Oral cyanocobalamin supplement administered as a 1000 mcg tablet taken once daily for 6 weeks. Used in patients with early-onset B12 deficiency during PPI therapy.

DRUGCyanocobalamin 1000 Mcg Sublingual Tablet

Sublingual cyanocobalamin supplement administered as a 1000 mcg tablet placed under the tongue once daily for 6 weeks. Used in patients with early-onset B12 deficiency during PPI therapy.

OTHERProton Pump Inhibitor therapy only

This group will continue their standard PPI therapy without receiving any vitamin B12 supplementation, serving as a control group for the comparison of B12 correction efficacy.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

DOUBLE (Subject, Caregiver)

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Age 18-70. * PPI use for 1-6 months (new users). * Serum B12 between 150-300 pg/mL. * No known prior B12 supplementation.

Exclusion criteria

* History of long-term GI disease (e.g., Crohn's, celiac). * Previous gastrectomy/bariatric surgery. * Baseline anemia with hemoglobin \<9 g/dL. * Severe renal or liver failure.

Design outcomes

Primary

Measure	Time frame	Description
Change in Serum Vitamin B12 Concentration	Baseline and Week 6	Measurement of serum vitamin B12 levels before and after 6 weeks of intervention to assess the efficacy of oral versus sublingual supplementation.

Secondary

Measure	Time frame	Description
Change in Plasma Homocysteine Level	Baseline and Week 6	Plasma homocysteine levels will be measured at baseline and at 6 weeks to assess the functional improvement in vitamin B12 status.
Change in Hemoglobin Level	Baseline and Week 6	To assess improvement in anemia, hemoglobin concentration will be measured at baseline and at 6 weeks.
Patient-Reported Satisfaction with Route of Supplementation	Week 6	At the end of the study, patients will be surveyed about their satisfaction and ease of use with the assigned supplementation route (oral or sublingual).

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026