Vitamin B12 Supplement to Prevent Cognitive Decline

The Chinese University of Hong Kong

Status and phase: Completed; Phase 4

Conditions: Cognitive Decline

Treatments: Dietary Supplement: Placebo; Dietary Supplement: Vitamin B12

Study type: Interventional

Funder types: Other

Identifiers

NCT02457507

DM-B12

Details and patient eligibility

About

Background: Older diabetic people are at greater risk of cognitive decline than non-diabetic people. Vitamin B12 deficiency in older people is associated with cognitive impairment and Alzheimer's disease. Vitamin B12 deficiency may therefore contribute to cognitive decline in older diabetic people.

Objective: To determine whether the correction of mild vitamin B12 deficiency in cognitively normal older diabetic people reduces the incidence of cognitive decline.

Design: randomized, double blind, placebo controlled trial Subject: Cognitively normal diabetic outpatients aged 70 years or older with plasma vitamin B12 150-300 pmol/L in medical and family medicine/ general outpatient clinics.

Procedure: After excluding those with clinical manifestations of vitamin B12 deficiency and without family member who can reliably inform on cognitive functioning (personal contact at least once a week), eligible patients will be invited to participate in this clinical trial. After obtaining written consent, research assistant (RA) will record demographic and clinical information from the subjects and perform neuropsychological tests - 1. Clinical dementia rating scale (CDR), 2. neurocognitive test battery (see below) 3. Chinese Mini mental state examination (MMSE), 4. Geriatric depression scale (GDS). Fasting blood will be taken for serum methylmalonic acid (MMA). Those with cognitive impairment and significant comorbidities will be excluded.

264 eligible subjects will be randomly assigned to take either two Vitamin B12 500 microgram or two identical looking placebo tablets once daily for 27 months.

All subjects or family caregivers are reviewed in the research clinic every 12 weeks in which the research assistant performs a pill count and dispenses the trial tablets. At 9 monthly intervals, the subjects will have neurocognitive test battery repeated at research clinic. CDR will be repeated at month 18 and 27. At month 9 and 27, fasting serum MMA and vitamin B12 will be repeated.

Enrollment: 271 patients

Sex: All

Ages: 70 to 100 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• >/= 70 years old
• B12: 150 - 300 pmol/L
• Caregiver (personal contact at least once a week)

Exclusion criteria

• Dementia
• Peripheral neuropathy
• Anaemia (Hb<10 g/dl)
• Renal failure (creatinine > 150 µmol/L
• Stroke

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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271 participants in 2 patient groups, including a placebo group

Vitamin B12

Experimental group

Description:

Vitamin B12, 1mg, daily, 27 months

Treatment:

Dietary Supplement: Vitamin B12

Placebo

Placebo Comparator group

Description:

Placebo comparator

Treatment:

Dietary Supplement: Placebo