ABSTRACT
Objective To explore the relationship between serum 25 (OH)D level and cognitive function in patients with Alzheimer's disease (AD).Methods Totally 113 AD impatients were enrolled in this study.Their serum 25 (OH) D2,25 (OH) D3,and total 25 (OH) D levels were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS).Patients were divided into Vitamin D severe deficiency group [25 (OH)D level≤25 nmol/L],deficiency group [25 (OH)D levels:25-50 nmol/L],insufficiency group [25 (OH) D level:50-75 nmol/L],and sufficiency group [25 (OH) D level ≥ 75 nmol/L] according to the criteria proposed by US Institute of Medicine.The cognitive function was assessed by MMSE score.The association between serum 25 (OH) D level and cognitive function was systematically analyzed.Results The serum levels of 25 (OH) D,25 (OH) D2,and 25 (OH) D3 were (27.08 ± 15.33) nmol/L,(1.23 ± 0.93) nmol/L and (24.50 ± 13.04) nmol/L in AD patients.The proportions of severe deficiency,deficiency,insufficiency,and sufficiency were 60.18％ (68/113),30.97％ (35/113),7.97％ (9/113),and 0.88％ (1/113),respectively,among these AD patients.A positive correlation was found between serum 25 (OH) D concentration and MMSE score in AD patients.Conclusions Impatients with AD often have severe vitamin D deficiency and need vitamin D supplementation.Serum 25 (OH) D concentration is associated with cognitive function,and therefore vitamin D supplementation may improve cognitive function.