Clinical Manifestations.

Background: Vitamin D deficiency is linked with the risk of developing dementia and Alzheimer disease. There is paucity of data on serum vitamin D level among patients from tropical countries such as Ethiopia. The objective of this study is to determine the prevalence of vitamin D deficiency and associated factors among Alzheimer disease and related dementia patients in Ethiopia.

Method: An institution-based cross-sectional study was conducted among patients presented with cognitive complaints and diagnosed with Alzheimer's disease or Alzheimer's disease related dementia at Lancet General Hospital in Addis Ababa, Ethiopia from November 1 - August 30, 2023. Sociodemographic and clinical data were obtained at presentation with serum vitamin D level determined subsequently. Cognitive test was assessed using the Montreal Cognitive Assessment-Basic (MOCA-B). Descriptive and inferential statistical analysis were done and measures of estimated crude and adjusted odds ratio with95% CI were constructed and a p value <0.05 was considered statistically significant.

Result: A total of 60 adult patients with dementia were enrolled. The mean (SD) age of dementia patients was 69.4 (1.56) years and 56% were male. The prevalence of vitamin D deficiency was 70% and the mean serum vitamin D level was 23.94 (1.55) ng/ml. Amnestic variant AD was detected in 45% of the participants followed by vascular dementia (35%) and Parkinson disease dementia (10%). HIV associated dementia was diagnosed in 6% of the participants. Hypertension was the most prevalent (45%) comorbidity reported in our dementia cohort. Severe vitamin D deficiency (serum vitamin D level < 10 ng/ml) was negatively association with disease severity (p = 0.01) and increased age (p = 0.003).

Conclusion: Vitamin D deficiency was prevalent in Ethiopian dementia patients. There were strong associations between severe vitamin D deficiency and dementia severity and increment in age.