The status of vitamins B6, B12, folate, and of homocysteine in geriatric home residents receiving laxatives or dietary fiber

J Nutr Health Aging. 2010 Mar;14(3):219-23. doi: 10.1007/s12603-010-0053-6.


Background: Vitamin B12 deficiency as a digestive disorder and constipation as a gastro motility disorder are common in the elderly. Laxative treatment is often chosen without regard for gut health.

Objective: To investigate whether the addition of oat-bran to the common oral diet for 12 weeks is able to reduce constipation and laxative use and improve gut health. It is assumed that this will lead to improved plasma levels of vitamins B6, B12, folate, and of homocysteine in nursing home residents.

Methods: A controlled, parallel intervention trial. 30 frail patients with multiple chronic diseases, aged 57-98 years, receiving laxative therapy were included. Patients were randomized into a fiber (n=15) and a control group (n=15). The intervention group received 5.2g/d oat-bran for 84 days mixed into the daily common meals. The control group received the ward's habitual diet. Food intake and laxative use were documented and blood samples (on day 01, day 42 and day 84) were collected. Vitamin B12 and folate were analyzed by radioimmunoassay, B6 and homocysteine by RP-HPLC with fluorescence detection, in addition to the routine lab test of albumin and CRP.

Results: In the fiber group, the intervention was well tolerated and laxative use decreased significantly (p < 0.001). In the control group, plasma B12 decreased faster (p < 0.05). In both groups, B6 and folate status remained unchanged. Plasma homocysteine decreased in both groups (p < 0.05). General mean energy intake was low (4861.4 kJ/d).

Conclusion: Oat-bran helps to improve constipation management and B12 bioavailability in elderly, with multiple chronic diseases who live in nursing homes.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Avena*
  • Biological Availability
  • Constipation / diet therapy*
  • Constipation / drug therapy
  • Dietary Fiber / therapeutic use*
  • Dietary Supplements
  • Energy Intake
  • Folic Acid / blood
  • Homocysteine / blood*
  • Humans
  • Laxatives / therapeutic use*
  • Middle Aged
  • Nursing Homes
  • Phytotherapy
  • Seeds
  • Vitamin B 12 / blood
  • Vitamin B 12 Deficiency / blood
  • Vitamin B 12 Deficiency / prevention & control
  • Vitamin B 6 / blood
  • Vitamin B Complex / blood*


  • Dietary Fiber
  • Laxatives
  • Homocysteine
  • Vitamin B Complex
  • Vitamin B 6
  • Folic Acid
  • Vitamin B 12