Samenvatting

Introduction According to the world health organization the number of older people is increasing. The number of older adults aged from 60 and beyond will be doubled in 2050 to 22% of the world’s population. Ageing is associated with involuntary loss of muscle mass, strength and physical function. This is referred to as sarcopenia. From the age of 40, the human body tends to lose muscle tissue, and therefore a loss of muscle mass and strength occurs. This decline of muscle tissue happens in a progressive fashion, which can lead up to 50% of tissue being lost at the age of 80. Sarcopenia can lead to severe consequences in older adults. Such as loss of function, disability, falls and mortality. Well-nourished older adults with a good nutritional state, are more likely to maintain muscle tissue during ageing. Vitamin D might play an important role in maintaining the muscle mass, strength and physical function. Therefore, the aim of the study is to assess the relation between the intake of vitamin D and the determinants of sarcopenia. Method The study population consists of the participants from the VITAMINE-project. This project included 224 older adults from Amsterdam area at baseline, of which 70% is female. The study is a quantitative observational study in a cross-sectional design. The independent study parameter is vitamin D intake. The dependent study parameters are the appendicular skeletal muscle mass, handgrip strength (HGS) and gait speed. These study parameters measure the three determinants of sarcopenia, muscle mass, muscle strength and physical function. The vitamin D intake is measured using the dietary intake and intake from supplements. Using a regression analysis, the relation between vitamin D and the determinants of sarcopenia is determined. The relation will also be corrected for potential confounders such as sex, age, level of education and activity level. Results Using a regression analysis the following results are found. With a difference of one microgram vitamin D intake, the SMI differs positively with 5.9% (p=0.328), the HGS differs positively with 52.2% (p=0.448) and the gait speed differs positively with 0.2% (p=0.921). However, non of those findings were significant. Based on the cut-off points for sarcopenia determined by the EWGSOP, 20 older adults in the study population can be diagnosed with sarcopenia, which equals 9.8% of the participants. The average intake of vitamin D of the sarcopenic older adults is 4.65 ± 4.98 mcg per day. The average intake of vitamin D of the non-sarcopenic older adults is 5.27 ± 6.42 mcg per day. This difference was not significant. Conclusion This study has shown a non-significant relation between the intake of vitamin D and the three determinants of sarcopenia in older adults in Amsterdam. This means that we cannot state that vitamin D has a positive significant relation to the prevalence of sarcopenia in older adults in Amsterdam.