Lifestyle habits and insufficient sunlight exposure lead to a high prevalence of vitamin
D hypovitaminosis, especially in the elderly. Recent studies suggest that in central Europe more
than 50% of people over 60 years are not sufficiently supplied with vitamin D. Since vitamin D
hypovitaminosis is associated with many diseases, such as Alzheimer’s disease (AD), vitamin D
supplementation seems to be particularly useful for this vulnerable age population. Importantly, in
addition to vitamin D, several analogues are known and used for different medical purposes. These
vitamin D analogues differ not only in their pharmacokinetics and binding affinity to the vitamin D
receptor, but also in their potential side effects. Here, we discuss these aspects, especially those of the
commonly used vitamin D analogues alfacalcidol, paricalcitol, doxercalciferol, tacalcitol, calcipotriol,
and eldecalcitol. In addition to their pleiotropic effects on mechanisms relevant to AD, potential
effects of vitamin D analogues on comorbidities common in the context of geriatric diseases are
summarized. AD is defined as a complex neurodegenerative disease of the central nervous system and
is commonly represented in the elderly population. It is usually caused by extracellular accumulation
of amyloidogenic plaques, consisting of amyloid (Aβ) peptides. Furthermore, the formation of
intracellular neurofibrillary tangles involving hyperphosphorylated tau proteins contributes to the
pathology of AD. In conclusion, this review emphasizes the importance of an adequate vitamin D
supply and discusses the specifics of administering various vitamin D analogues compared with
vitamin D in geriatric patients, especially those suffering from AD