Vitamin D status and physical function in older Finnish people: A one-year follow-up study
Introduction
Vitamin D deficiency is a public health problem worldwide (Mithal et al., 2009). Approximately 50–70% of community-dwelling older people in Europe have vitamin D deficiency, as defined by serum 25-hydroxyvitamin D (25OHD) of less than 50 nmol/l (Chan & Woo, 2011). In Finland, vitamin D intake and vitamin D status has been low in all age groups (Lamberg-Allardt, Brustad, Meyer, & Steingrimsdottir, 2013).
There is increasing evidence to show that vitamin D deficiency is an important risk factor for various adverse health outcomes (Holick, 2007, Lamberg-Allardt et al., 2013). Evidence of the role of 25OHD in relation to physical function (PF), and especially in relation to changes in PF, is limited. Although many cross-sectional studies have shown that low 25OHD concentrations are associated with lower physical performance and muscle strength (Dukas, Staehelin, Schacht, & Bischoff, 2005; Gerdhen, Ringsberg, Obrant, & Akesson, 2005; Wicherts et al., 2007; Dam, von Mühlen, & Barrett-Connor, 2009; Shahar, Levi, & Kurtz, 2009; Pramyothin et al., 2009, Dretakis et al., 2010, Houston et al., 2011, Houston et al., 2012, Mastaglia et al., 2011, Michael et al., 2011, Boersma et al., 2012, Menant et al., 2012, Toffanello et al., 2012, Boyé et al., 2013, Gschwind et al., 2014; Janssen, Emmelot-Vonk, Verhaar, & van der Schouw, 2013), others have found no association (Annweiler et al., 2009, Chan et al., 2012, Mathei et al., 2013). The results of few longitudinal studies with 2–4-year follow-ups are inconsistent, some showing low 25OHD levels to be associated with decline in physical performance and muscle strength (Visser, Deeg, & Lips, 2003; Wicherts et al., 2007, Dam et al., 2009, Houston et al., 2011) while others show no association (Verreault et al., 2002, Michael et al., 2011, Chan et al., 2012, Houston et al., 2012).
The objective of this study was to describe the cross-sectional associations between 25OHD and PF and associations between 25OHD and changes in PF during 12 months in Finnish community-dwelling people aged 65 and older.
Section snippets
Participants, settings and study design
The subjects (n = 591) were community-dwelling older persons living in Pori, Finland who participated in a risk-based multifactorial fall prevention trial (ID = NCT00247546). The inclusion criteria were: age 65 years or over, at least one fall during the previous 12 months, sum score in the Mini Mental State Examination test (MMSE) ≥ 17, able to walk 10 m independently with or without walking aids, and living at home or in sheltered housing (Sjösten et al., 2007). The 12-month fall prevention program
Results
A total of 518 participants (79 men and 439 women) were included in the analysis. Excluded participants (with a missing data of 25OHD and/or PF) were older, and their physical function was lower than that of included in the study. Also comorbidity was more common among those excluded from the study. Detailed data of drop-out analysis are shown in Table 1.
The baseline data of 518 participants of the study are shown in detail in Table 2. 25OHD deficiency (<50 nmol/l) was found in 20.5% of the
Discussion
In our study, one fifth of community-dwelling older adults had 25OHD deficiency (<50 nmol/l), and lower 25OHD concentration were associated with poorer PF in both cross-sectional and prospective analyses. Differences in PF and in changes of PF were most obvious between subjects with 25OHD <50 nmol/l and those with 25OHD ≥75 nmol/l.
The results of our study supported strong cross-sectional evidence on the association of 25OHD deficiency (<50 nmol/l) and lower PF among older subjects (Dukas et al.,
Conclusions
In conclusion, low 25OHD concentrations predicted deterioration in PF during 12 months among community-dwelling older Finnish men and women. The results of this study and some earlier studies (Wicherts et al., 2007, Houston et al., 2011) indicated that 25OHD should be at least 75 nmol/l in order to prevent decline in PF among community-dwelling older people.
Conflict of interest
None.
Acknowledgements
The study has been funded by Southwestern Finland Hospital District, Satakunta Hospital District, The Päivikki and Sakari Sohlberg Foundation, The Juho Vainio Foundation and the Academy of Finland.
References (31)
- et al.
Is there an association between serum 25-hydroxyvitamin D concentration and muscle strength among older adults? Results from baseline assessment of the EPIDOS study
The Journal of Nutrition Health and Aging
(2009) - et al.
Vitamin D status in relation to postural stability in the elderly
The Journal of Nutrition Health and Aging
(2012) - et al.
‘Mini-mental state’. A practical method for grading the cognitive state of patients for the clinician
Journal of Psychiatric Research
(1975) - et al.
Effect of vitamin D nutritional status on muscle function and strength in healthy women aged over sixty-five years
The Journal of Nutrition Health and Aging
(2011) - et al.
A multifactorial fall prevention programme in home-dwelling elderly people: a randomized-controlled trial
Public Health
(2007) - et al.
Vitamin D and physical performance in older men and women visiting emergency department because of a fall: data from the improving medication prescribing to reduce risk of falls (IMPROveFALL) study
Journal of the American Geriatrics Society
(2013) - et al.
The value of vitamin D supplementation in older people
Nutritional Therapy & Metabolism
(2011) - et al.
Not all elderly people benefit from vitamin D supplementation with respect to physical function: results from the osteoporotic fractures in men study, Hong Kong
Journal of the American Geriatrics Society
(2012) - et al.
Sex-specific association of serum vitamin D levels with physical function in older adults
Osteoporosis International
(2009) - et al.
Correlation between serum 25-hydroxyvitamin D levels and quadriceps muscle strength in elderly Cretans
Journal of International Medical Research
(2010)