A study developed by researchers from the departments of physiotherapy (DFisio) and gerontology (DGero) of UFSCar has identified that there is a relationship between low blood levels of vitamin D and the risk of developing functional disability in activities. instruments of daily life (IADL) in Men.
The research was developed by Mariane Marques Luiz, currently a doctoral student in physiotherapy at UFSCar, under the supervision of Tiago da Silva Alexandre, professor at DGero at UFSCar and coordinator of the International Collaboration for Longitudinal Studies in Aging (InterCoLAging ), a Longitudinal Studies Consortium, which covers the English Longitudinal Study of Aging (ELSA Study), a large longitudinal study of the health of older people in England. The study also involved researchers from University College London (UCL) in the UK.
IADLs are daily activities that require a higher level of complexity and attention when performing them, such as household activities, managing finances, and the ability to use means of transport and communication. These activities are essential for maintaining the functional capacity of older people, which reflects the ability to independently meet the physical demands of daily life.
According to the researchers, previous studies have already identified that low blood levels of vitamin D impair functional ability, as they impair performance in the basic activities of daily living (BADL), which are those related to personal care such as eating. , wash and dress. .if. However, it had not yet been verified whether vitamin D deficiency would also be associated with a higher risk of developing disability specifically in IADLs. According to Mariane Luiz, “the research aimed to determine whether vitamin D deficiency was a risk factor for developing disability in IADLs and to verify whether this risk occurred differently between men and women”.
To this end, 4,768 English individuals participating in the ELSA study, aged 50 or over, having had no difficulty in any of the following IADLs: managing finances, using means of transport, shopping, preparing meals, use of telephone/means of communication were assessed. , manage medications and do household chores. Subjects had their vitamin D blood levels categorized as sufficient, insufficient, or deficient and collected other information such as socioeconomic data, lifestyle habits, and health conditions. After four years of follow-up, these individuals were reassessed to see if there was any development of difficulty performing one or more of the IADLs. According to the author of the study, at the end of the four years of follow-up, no association was found between vitamin D deficiency and the incidence of disability in IADL in women. However, vitamin D deficiency increased the risk of developing disability in men by 43%.
Tiago Alexandre explains “that vitamin D has an important action for the functioning of the muscles and, when its levels are low, it leads to muscle weakness and atrophy, which compromises performance in daily activities, leading to difficulties in IADL” . He also points out that “vitamin D plays a protective action on the central nervous system and its deficiency has been proven to promote cognitive decline, which may explain the poorer performance in IADL, since these are activities that require cognitive capacity. preserved”.
The authors suggest that the results found only for men may be due to the association between vitamin D and testosterone. “Men experience greater muscle fiber atrophy than women due to declining testosterone levels with age. Since vitamin D contributes to testosterone production, its deficiency can intensify muscle atrophy in these individuals. “, they report. The researchers add that testosterone has a protective effect on cognitive abilities and that the reduction in its level, accentuated by vitamin D deficiency, could promote earlier cognitive decline in men. “Thus, the worst muscular and cognitive performance in these individuals may be associated with disability in IADL”, underline Mariane Luiz and Tiago Alexandre.
The research concluded that vitamin D deficiency represents an early indicator of functional impairment in the elderly and the authors point out that this deficiency is a modifiable condition. Additionally, they point out that monitoring vitamin D levels may be a strategy to prevent IADL difficulties and prevent the development of disability in older adults.
The authors caution that the results found may be similar in the Brazilian scenario and that assessment of vitamin D levels should be done by measuring 25-hydroxyvitamin D (25OHD) concentrations in the blood. Although the main source of vitamin D is exposure to the sun, when its levels are deficient, vitamin D supplementation should be a treatment strategy, to be prescribed only by nutritionists and physicians.
The study was financed by the Fundação de Amparo at Pesquisa do Estado de São Paulo (FAPESP), the Coordination for the Development of Higher Education Personnel (Capes) and the National Council for Scientific and Technological Development (CNPq) . Recently, the research was published in Nutrients, a renowned nutrition journal. The full article is available on this link (https://bit.ly/3zu3Z0e).