Vitamin D in the elderly: 5 points to remember

Meta-Analysis of Memory and Executive Dysfunctions in Relation to Vitamin D

“…As already reported in the field of vitamin D research [1,3], the definition of 'lower' and 'higher' 25OHD status may vary depending on the study and population (for details, see Tables 2a and 2b), and was based either on threshold values defined a priori or on populationbased quantiles. When the same cognitive test was used in 3 or more studies, a summary measure of the mean difference with a 95% CI was calculated.…”

“…For example, even if most cohorts included only older adults aged 65 years and older, some also tested middle-aged or even younger adults, with various proportions [20,22,24,25,27,28,34,36]. Age is known to increase the risks of both cognitive decline [18] and hypovitaminosis D [1][2][3]54]. It seems therefore crucial to focus on a homogeneous age group while assessing the neurological effects of vitamin D, especially since it has been suggested that the neuroprotective effects of vitamin D increase with the advance in age [4].…”

“…Nevertheless, it has been reported that the polymorphic variants of VDR gene may account for a number of sex-dependent health issues, such as growth or type 1 diabetes mellitus [55,56]. Vitamin D regulates the expression of target tissues including the brain by binding the VDRs, which are transcription factors regulating gene expression [1,3,4]. It could therefore be proposed that some allele combinations offer greater protection against cognitive decline in women compared to men.…”

“…Hypovitaminosis D is a highly prevalent condition, with an estimated prevalence of approximately 1 billion adults worldwide [1][2][3]. Beyond its well-known detrimental impact on bone health, the severity of hypovitaminosis D correlates with reduced vitamin D activity in a variety of organs, including the central nervous system [1][2][3][4].…”

“…Beyond its well-known detrimental impact on bone health, the severity of hypovitaminosis D correlates with reduced vitamin D activity in a variety of organs, including the central nervous system [1][2][3][4]. At this level, vitamin D exerts action through its nuclear hormone receptor, the vitamin D receptor (VDR), expressed in neurons and glial cells of hippocampus, hypothalamus, cortex, and subcortex [3,4]; all areas essential for cognition. A number of actions have been described including anti-inflammatory and antioxidant effects, as well as the regulation of genetic expression of neurotrophins and neurotransmitters [4][5][6][7][8].…”