Vitamin D Serum Level in Elderly Patients with Alzheimer’s Disease: Preliminary Analysis from Cilento Region

It is estimated that 46 million people in the world live with dementia and it is estimated that this number will increase 3-fold by 2050, being a leading cause of disability worldwide and major welfare and economic problem. The aging of the general population increase these problems, especially in regions, such as Cilento (Southern Italy), where we can register higher longevity. Preserving cognitive health is one of the most important aims of the current research, also through the identification of possible preventative life-style strategies. Recent meta-analyses suggest that low serum vitamin D concentrations could be associated with Alzheimer's disease (AD) and cognitive impairment. The specific role of Vitamin D, however, is still controversial. There is a growing evidence of high rates of vitamin D deficiency in the elderly and there is still much uncertainty about the cause of AD and other forms of dementia. On the other hand, there is no definitive evidence is not conclusive and vitamin D could be involved in many other physiological and pathological mechanisms.

Our aim is to investigate vitamin D serum levels in a small preliminary sample of AD patients from the Cilento area.

Patients were recruited from the AD centre of the San Luca Hospital, in Vallo della Lucania (SA). We enrolled 25 consecutive patients, 13 women, and 12 men. The mean age was 78.5±8.3 years, the mean duration of the disease was 3.5±1.8 years. The average school-age of the patients was 6.1 +/- 3.5 years, the average disease age was 6.3 +/- 1.7 years, the average basal Mini-Mental Score Examination (MMSE) score was 17.6 +/- 3.6. We determined serum 25-hydroxyvitamin D (25[OH]D) in 25 consecutive AD patients.

The mean vitamin D serum level was 17.9+7.9 UI/ml, denoting a state of insufficiency. Among our 25 patients, only 3 had serum level above 30 UI/ml; most patients (17 out of 25) showed serum level among 10 and 30 UI, while in 5 patients, serum level was less than 10 UI.

Our preliminary data showed that Vitamin D deficiency was, in our patients, independently associated with AD, even in a special population, high rate of centenarians, like Cilento people. However, our preliminary study has different limitations. The vitamin D deficiency has been evaluated through a single time-point of measurement (or in different periods of the year), that may be susceptible to bias. Even the differences in age and level of education should be taken into consideration. Nevertheless, these data in the Cilento region are original (there are no similar reports to our knowledge). However, our results confirm the necessity of other study, and this result is an important opportunity to introduce a modifiable risk fact and, consequently, a new treatment for AD.