Vitamin D Status of Institutionalized Patients with Alzheimer's Disease

Abstract

The risk of vitamin D deficiency in an elderly population is well documented. Age related changes, dietary intake and sun exposure are some of the primary influences that determine vitamin D status. Ninety-eight patients with the diagnosis of probable dementia of the Alzheimer type, (2 women and 96 men) ranging in age from 48–90 years were screened for vitamin D deficiency by measuring serum 25-hydroxyvitamin D levels. The mean vitamin D content of all hospital diets provided to the patient sample was 361IU, which is less than the RDA for people >51 years of age.Twelve percent were found to have a severe clinical deficiency <1 Ing/ml and another 29% had a moderately low vitamin D level of < 20ng/ml. The most influential factors to predict low vitamin D status were mobility status and level of eating ability as indicated by the texture modification of the diet. The patients that maintained their chewing ability had a mean serum vitamin D level of 26.1 ng/ml, while patients who needed thickened liquids to enhance swallowing had a mean serum vitamin D level of 13.0 ng/ml. The patients who were able to ambulate independently had a mean serum vitamin D level of 23.9 ng/ml while bedfast patients had a mean serum D level of 15.6 ng/ml. Administration of phenytoin did not increase risk for low serum vitamin D levels.These results show that patients with dementia are at increased risk for a vitamin D deficiency when they lose their ability to ambulate and develop swallowing difficulties. However with appropriate dietary adjustments and skilled feeding techniques, it is possible to maintain adequate vitamin D status.