Low plasma vitamin C in Alzheimer patients despite an adequate diet

Int J Geriatr Psychiatry. 1998 Nov;13(11):749-54. doi: 10.1002/(sici)1099-1166(1998110)13:11<749::aid-gps860>3.0.co;2-t.


Objective: To compare the vitamin C and E plasma levels in patients with Alzheimer's disease (AD) and to assess the vitamin C intake and nutritional status.

Design: Case-control study. Four groups of sex- and age-matched subjects were compared: severe AD and moderate AD, in patients with moderate AD and controls.

Setting: Community and hospitalized patients in the region of Toulouse, France.

Participants: Patients with dementia who fulfilled criteria for Alzheimer's disease: severe Alzheimer group (N = 20), Mini-Mental State Examination (MMSE) score range 0-9; moderate Alzheimer group (N = 24), MMSE 10-23; hospitalized Alzheimer group (N = 9), MMSE 10-23. Control group (N = 19), MMSE 24-30.

Measures: Plasma vitamin E and C were quantified by HPLC-fluorescence. Consumption of raw and cooked fruit and vegetables was evaluated in order to determine the mean vitamin C intakes. Mini Nutritional Assessment (MNA) and plasma albumin were used to measure nutritional status.

Results: Institutionalized and community subjects were analysed separately. MNA scores were normal in home-living Alzheimer subjects with moderate dementia and significantly lower in those with severe disease, despite normal plasma albumin levels. In the home-living Alzheimer subjects, vitamin C plasma levels decreased in proportion to the severity of the cognitive impairment despite similar vitamin C intakes, whereas vitamin E remained stable. The hospitalized Alzheimer subjects had lower MNA scores and albumin levels but normal vitamin C intakes, but their plasma vitamin C was lower than that of community-living subjects. Institutionalized Alzheimer subjects had significantly lower MNA scores but normal vitamin C and albumin levels and vitamin C intakes compared with community-dwelling subjects of similar degree of cognitive impairment.

Conclusion: Plasma vitamin C is lower in AD in proportion to the degree of cognitive impairment and is not explained by lower vitamin C intake. These results support the hypothesis that oxygen-free radicals may cause damage.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / blood
  • Alzheimer Disease / diagnosis*
  • Ascorbic Acid / blood*
  • Ascorbic Acid Deficiency / blood
  • Ascorbic Acid Deficiency / diagnosis*
  • Female
  • France
  • Geriatric Assessment
  • Humans
  • Male
  • Mental Status Schedule
  • Middle Aged
  • Nutrition Assessment*
  • Reference Values
  • Social Environment
  • Vitamin E / blood


  • Vitamin E
  • Ascorbic Acid