Volume 176 - Issue 11
Vitamin D deficiency is common in frail institutionalised older people in northern Sydney
Authors: Philip N Sambrook, Ian D Cameron, Robert G Cumming, Stephen R Lord, Jennifer M Schwarz, Angelika Trube and Lynnette M March
Med J Aust 2002; 176 (11): 560. || doi: 10.5694/j.1326-5377.2002.tb04557.x
Published online: 3 June 2002
Published online: 3 June 2002
To the Editor: Although treatment with vitamin D has been shown to reduce hip fracture risk in elderly institutionalised people,1 there has been a perception that vitamin D deficiency is generally uncommon in countries with high sunlight exposure such as Australia.
We studied the prevalence of vitamin D deficiency in older people in residential aged-care facilities (hostels and nursing homes) in the northern Sydney area as part of the FREE study (Fracture Risk Epidemiology in the Elderly), a prospective study of fracture incidence in more than 2000 participants. Here, we report baseline serum 25(OH) vitamin D concentrations in the first 386 participants, determined in partially purified lipid extracts using a competitive protein binding assay.2
The sample comprised 252 women and 134 men (mean ± SE age, 86.7 ± 0.6 v 81.2 ± 0.7 years, respectively; P < 0.001). The mean serum 25(OH)D level was 17 nmol/L (SD, 12) and median serum 25(OH)D level was 15 nmol/L (interquartile range, 9 to 22). Vitamin D deficiency (defined as a serum 25(OH)D concentration < 28 nmol/L) was present in 86% of women and 68% of men. There was no significant difference in serum vitamin D levels between women in nursing homes versus women in hostels, nor between men in nursing homes versus those in hostels. Although serum vitamin D levels were low throughout the year, a small rise was observed in summer (P < 0.01). Length of stay in the residential facility was not a predictor of serum vitamin D level. Mean parathyroid hormone levels were 93 pg/mL (normal range, 12–72 pg/mL) and rose when vitamin D levels dropped below 21 nmol/L, indicating secondary hyperparathyroidism.
A number of previous studies have suggested a high prevalence of vitamin D deficiency in older institutionalised Australians in southern States,2-4 but we are unaware of any published studies in Sydney (latitude 33°S). However, as the prevalence of vitamin D deficiency in older people living in the community in Geelong is low,5 our study suggests that factors like confinement indoors is more important than latitude.
Given the relationship between vitamin D status and fracture, with more than 72 500 nursing home residents and 60 200 hostel residents in Australia in 1997, our findings indicate that vitamin D deficiency represents a significant public health problem in elderly institutionalised Australians regardless of geographical location. Importantly, this problem could be solved relatively simply by measures such as a short period of daily sunlight exposure or giving moderate doses of vitamin D annually to nursing home and hostel residents.
Acknowledgements
This study was funded by a grant from the National Health and Medical Research Council.
References
- Chapuy MC, Arlot ME, Duboeuf F, et al. Vitamin D3 and calcium to prevent hip fractures in elderly women. New Engl J Med 1992; 327: 1637-1642.
- Du X, Greenfield H, David DR, et al. Vitamin D deficiency and associated factors in adolescent girls in Beijing. Am J Clin Nutr 2001; 74: 494-500. i1149922
- Stein M, Wark JD, Scherer SC, et al. Falls relate to vitamin D and parathyroid hormone in an Australian nursing home and hostel. J Am Ger Soc 1999; 47: 1195-1201. pgfId-1187709
- Inderjeeth CA, Niklason F, Al-Lahham Y, et al. Vitamin D deficiency and secondary hyperparathyroidism: clinical and biochemical associations in older non-institutionalised southern Tasmanians. Aust N Z J Med 2000; 30: 209-214. i1149925
- Pasco JA, Henry MJ, Nicholson GC, et al. Vitamin D status of women in the Geelong Osteoporosis Study: association with diet and casual exposure to sunlight. Med J Aust 2001; 175: 401-405. i1149927