Efficacy of Supplemental Oral Cyanocobalamin Versus Methylcobalamin for Maintaining Serum Cobalamin Levels in Post-gastrectomy Patients

Status

Recruiting

Phases

Phase 4

Study type

Interventional

Source

TCTR

Registry ID

TCTR20251027015

Enrollment

Registered

2025-10-27

Start date

2025-05-28

Completion date

Unknown

Last updated

2026-08-03

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

Conditions

serum vitamin B12 level in patients who have undergone gastrectomy serum vitamin B12, serum cobalamin, gastrectomy

Interventions

oral cyanocobalamin 1,000 mcg/day for 3 months,oral methylcobalamin 1000 mcg/day for 3 months

Experimental Drug,Active Comparator Drug

oral cyanocobalamin,oral methylcobalamin

Eligibility

Sex/Gender

All

Age

20 Years to No maximum

Inclusion criteria

Inclusion criteria: 1. age from 20 years 2. undergone gastrectomy

Exclusion criteria

Exclusion criteria: 1. Unable to take oral vitamin B12 supplements 2. Has vitamin B12 deficiency (< 200 pg/ml) accompanied by clinical symptoms 3. History of distal small bowel resection 4. Has other causes of abnormal vitamin B12 absorption, such as severe mucosal disease, short bowel syndrome, or chronic intestinal failure 5. Has received intramuscular vitamin B12 treatment within the past 3 months

Design outcomes

Primary

Measure	Time frame
vitamin B12 level at 3 months after end of the intervention serum vitamin B12 level	—

Secondary

Measure	Time frame
N/A N/A N/A	—

Countries

Thailand

Contacts

Public ContactNeera Munsakul

Phramongkutklao Hospital

neeranam14@gmail.com0877167510

Outcome results

None listed

Source: TCTR (via WHO ICTRP) · Data processed: Aug 10, 2026