Vitamin D deficiency and secondary hyperparathyroidism: clinical and biochemical associations in older non-institutionalised Southern Tasmanians

Nutritional status and functionality in geriatric rehabilitation patients: a systematic review and meta-analysis

PURPOSE

Since there is only limited evidence available for geriatric rehabilitation patients, this systematic review and meta-analysis aims to characterize the nutritional status in this population and its relationship with functionality.

METHODS

Eight databases were searched for full-text articles reporting baseline nutritional intake and status of adults ≥ 60 years in rehabilitation settings. Pooled estimates were calculated for prevalence of malnutrition and risk of malnutrition based on the Mini Nutritional Assessment (MNA) and for mean body mass index (BMI). Associations between nutritional status (MNA, MNA short form and BMI) and functional status (Barthel Index and Functional Independence Measure) and prevalence of sarcopenia were reviewed.

RESULTS

62 out of 1717 references were eligible for inclusion. Pooled prevalence [95% confidence interval (CI)] of malnutrition and risk of malnutrition were 13 (5-20) % and 47 (40-54) %. Pooled estimate (95% CI) for BMI was 23.8 (23.2-24.5) kg/m2. Existing data suggest a risk for low protein and energy intake and vitamin D deficiency. Functional status differed widely. Seven out of ten studies reported significant associations between reduced nutritional status and reduced functionality, whilst two out of seven studies reported significant associations between higher BMI and functionality. Prevalence of sarcopenia was high with 40-76% in this population.

CONCLUSIONS

Although geriatric rehabilitation populations and settings were heterogeneous, a relevant percentage of geriatric rehabilitation patients were affected by a reduced nutritional status. Nutritional status was associated with decreased functionality. This emphasizes the need for screening for malnutrition and targeted nutritional intervention.

Adjunctive Vitamin D in the treatment of non-remitted depression: Lessons from a failed clinical trial

BACKGROUND

Many patients with depression fail to achieve remission after several consecutive treatments. Vitamin D deficiency is prevalent and new research suggests that it may have an impact on mood, primarily through an effect on neurotransmitters. Numerous observational studies suggest a relationship between low levels of vitamin D and increased incidence and severity of mood disorders. A small number of pilot studies have been undertaken but lack rigorous methodology required to draw conclusions about a clinical role for this nutrient in treatment resistant depression.

METHODS

This study was designed as a randomized, double-blind, placebo controlled intervention study administering a weekly (bolus) dose of 28 000IU of Vitamin D3 or placebo to 125 patients with non-remitted depression adjunct to current antidepressant medication. Patients were followed weekly for eight weeks plus a one month follow up. Outcomes measured included depression severity, serum vitamin D levels and safety. Due to slow recruitment during the first season, amendments were made. These included extending the age range to 18-75 and removing the requirement for failing to respond to one pharmacologic antidepressant agent. The protocol was amended to reduce the burden on participants by changing the in-office visits to bi-weekly. Three additional tertiary psychiatric clinics were also added as trial sites.

RESULTS

Over three recruitment period years (fall/winter), a total of 148 participants completed screening, 24 (16.2%) of whom qualified to participate in the study. Use of too many or no psychiatric medications, comorbid exclusionary psychiatric conditions, current use of a vitamin D supplement, and lack of participant compensation were the predominant reasons for ineligibility or unwillingness to participate. 9 participants were successfully enrolled in the study, 7 (77.8%) of whom completed the trial as per the protocol. After the third season, futility was declared based on inability to enroll participants. The sample size of enrolled participants (7/125, 5.6%) lacks power to conduct a full assessment of findings.

DISCUSSION

High accessibility of vitamin D, as well as a growing lack of equipoise in patients and clinicians about the potential ubiquitous benefits of vitamin D for Canadians, not just for mood disorders, resulted in a large proportion of ineligible potential participants. Limited funding provided to studies on natural health products hampered recruitment. The labile and fluctuating nature of non-remitted depression as well as frequent co-morbid conditions creates additional challenges for conducting trials in this population. Future studies assessing vitamin D in depression should consider our experiences in design and conduct of research. Innovations in clinical trial design such as preference trials or accepting patients already using vitamin D but not achieving an optimal target value are potential solutions to some of these challenges.

Assessment of physical activity in patients with chronic kidney disease and renal replacement therapy

This study aimed to create a unique assessment tool to investigate the physical activity levels of patients suffering from chronic kidney disease (CKD). Previous studies have documented a lack of physical activity within patients living with CKD and patients on renal replacement therapy (RRT). Physical activity plays a key role in the prevention and management of cardiovascular disease (CVD). Patients with CKD are at high risk of developing CVD. Physical inactivity can be considered as a major modifiable risk factor for CVD in CKD patients. In this study 100 patients completed the 20 item questionnaire which produced a total activity score (TAS) and activity loss score for each patient. Bio-chemical markers, haemoglobin, erythropoietin therapy and co-morbidities were documented for each patient. Results were compared against 50 age, sex-matched controls. Results showed a significant difference in TAS between in-centre haemodialysis (ICHD) patients and the healthy control group. A significant difference was also seen with the home haemodialysis (HD) and ICHD patients against the transplant group (TX). Our quick assessment tool identified the ICHD patients as the most physically inactive group within the CKD and RRT population compared to a healthy control group. We therefore recommend that doctors encourage physical activity within this high risk group and start 'prescribing exercise' to their patients.

Low vitamin D status is an independent predictor of increased frailty and all-cause mortality in older men: the Health in Men Study

CONTEXT AND OBJECTIVE

Hypovitaminosis D and frailty are common in the older population. We aimed to determine whether 25-hydroxyvitamin D [25(OH)D] concentrations are associated with frailty and mortality.

DESIGN

We conducted a prospective cohort study.

SETTING AND PARTICIPANTS

Participants included 4203 older men aged 70-88 years in Perth, Western Australia.

MAIN OUTCOME MEASURES

25(OH)D was measured by immunoassay. Frailty was assessed with the 5-point FRAIL (fatigue, resistance, ambulation, illness, and loss of weight) scale. Mortality was determined from the death registry via the Western Australian Data Linkage System.

RESULTS

At baseline, 676 (16.1%) men were frail, as defined by having ≥3 deficits (FRAIL scale ≥ 3). In multivariate cross-sectional analysis, low vitamin D status, defined by the lowest quartile of 25(OH)D values (<52.9 nmol/L), was associated with increased prevalent frailty (odds ratio, 1.96; 95% confidence interval [CI], 1.52 to 2.52) in comparison to the highest quartile of 25(OH)D values (>81.6 nmol/L). After a mean period of 5.3 years, the adjusted odds ratio of being frail at follow-up for men with low vitamin D and having zero deficit at baseline (FRAIL scale = 0) was 1.56 (95% CI, 1.07 to 2.27). Low vitamin D also predicted all-cause mortality over a period of up to 9.2 years (hazard ratio, 1.20; 95% CI, 1.02 to 1.42), independent of baseline frailty and other covariates.

CONCLUSION

Hypovitaminosis D is associated with prevalent and incident frailty in older men. Hypovitaminosis D also predicts all-cause mortality, independent of frailty. The association between vitamin D and mortality is not solely dependent on the occurrence of frailty.

Serum 25-hydroxy vitamin D levels in relation to body mass index: a systematic review and meta-analysis

BACKGROUND

Although several cross-sectional studies have investigated serum vitamin D levels in relation to body mass index (BMI), findings are inconsistent.

OBJECTIVE

This systematic review and meta-analysis of published cross-sectional data was conducted to summarize the evidence on the link between serum vitamin D levels and BMI in adults.

METHODS

PubMed, ISI Web of Science, Scopus and Google scholar database were searched to May 2012 for all relevant published papers. We found 34 articles that reported the correlation coefficients between serum 25-hydroxy vitamin D (25(OH)D) levels and BMI in apparently healthy adults (>18 years). The primary analysis was done on these 34 papers that reported 37 correlation coefficients. To find the source of between-study heterogeneity, our secondary analysis was confined to eight studies that had used random sampling method and reported the correlations for the whole population.

RESULTS

Our meta-analysis on 34 relevant papers revealed an overall significant inverse, but weak, association between serum 25(OH)D levels and BMI (Fisher's Z = -0.15, 95% CI: -0.19, -0.11) with a significant heterogeneity between studies. In the subgroup analysis based on gender and study location (East vs. West), the inverse associations were significant in both genders (male: Fisher's Z = -0.11, 95% CI: -0.14, -0.08 and female: -0.14, 95% CI: -0.21, -0.08) and both study locations (East: -0.09, 95% CI: -0.14, -0.04 and West: -0.23, 95% CI: -0.31, -0.17). In the subgroup analysis based on developmental status of countries, the weak inverse association remained significant in developed countries (-0.17, 95% CI: -0.21, -0.14), but not in developing nations (-0.10, 95% CI: -0.20, 0.01). Using meta-regression, we found that latitude (P = 0.91) or longitude (P = 0.2) of cities did not significantly contribute to the computed effect sizes. When we restricted our analysis to eight selected studies that used random sampling method, we reached the same findings. In this analysis, gender and developmental status of countries explained the between-study heterogeneity.

CONCLUSION

There is a significant inverse weak correlation between serum 25(OH)D levels and BMI in adult population, except for women living in developing countries. Further research particularly in developing countries and populations living near the equator is needed.

Significant perturbation of vitamin D-parathyroid-calcium axis and adverse clinical outcomes in critically ill patients

PURPOSE

A prospective multicentre cohort study was conducted to determine the prevalence of hypovitaminosis D in adult critically ill patients, to characterize alterations in the parathyroid hormone (PTH)-vitamin D-calcium axis and to explore associations between hypovitaminosis D and adverse clinical outcomes.

METHODS

Demographic, disease severity scores and clinical outcome data were collected in 100 consecutive patients with expected intensive care unit (ICU) admission of at least 2 days. Levels of 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D (1,25-(OH)(2)-D), PTH and ionized calcium were measured on days 1, 3 and on day 7 or ICU discharge.

RESULTS

The prevalence of vitamin D insufficiency (25 nmol/L ≤ 25-OH-D ≤ 50 nmol/L) and deficiency (25-OH-D < 25 nmol/L) were 54 and 24 %, respectively, and levels did not recover during ICU stay. Admission 25-OH-D levels correlated with 1,25-(OH)(2)-D (R = 0.61, p = 0.001), Simplified Acute Physiology Score (SAPS-II) (R = -0.3, p = 0.01), Acute Physiology and Chronic Health Evaluation (APACHE-II) scores (R = -0.2, p = 0.05), but not calcium (R = 0.16, p = 0.11) or PTH (R = -0.11, p = 0.31) levels. Vitamin D deficiency was associated with fewer hospital-free days, OR 3.15 (1.18-8.43) in univariate analysis. Secondary hyperparathyroidism (PTH > 7 pmol/L) was observed in 37.5 % of hypocalcaemic and 32.5 % of vitamin D insufficient/deficient patients, and was associated with higher SAPS-II [43 (31.3-60) vs. 36 (30-43), p = 0.03].

CONCLUSIONS

Hypovitaminosis D and secondary hyperparathyroidism are highly prevalent in critically ill patients. Low vitamin D status persists during ICU stay and is associated with worse disease severity and fewer hospital-free days.

The prevalence of vitamin D deficiency and relationship with fracture risk in older women presenting in Australian general practice

AIM

To investigate vitamin D status among older women and to explore relationships between vitamin D and fracture risk and vertebral fractures.

METHODS

A total of 267 general practitioners recruited 2466 women aged >70 years with no known osteoporosis or fragility fracture. Serum 25-hydroxy vitamin D (25(OH)D), bone mineral density by dual-energy X-ray absorptiometry (DXA) and vertebral fracture on thoracolumbar X-ray were determined.

RESULTS

A total of 2368 women, median age 76 years, provided data and of these 13% were on vitamin D supplements. 25(OH)D levels were available for 907 (44.1%) of those not taking vitamin D. 88.3% of these had a level below 75 nmol/L. Serum 25(OH)D was negatively associated with age (P = 0.003) and body mass index (P < 0.001), and positively associated with lower latitude, femoral neck DXA T-score (P = 0.044) and being Caucasian (P < 0.001).

CONCLUSIONS

The vitamin D status of community-dwelling older Australian women is inadequate, yet the use of supplements is low.

Global vitamin D status and determinants of hypovitaminosis D

This review describes the vitamin D status in different regions of the world with the objective of understanding the scope of hypovitaminosis D and the factors related to its prevalence that may contribute to the pathogenesis of osteoporosis and fragility fractures.

INTRODUCTION

Vitamin D status has been linked to the pathogenesis of hip fractures as well as other skeletal and non-skeletal disorders. The purpose of this review is to provide a global perspective of vitamin D status across different regions of the world and to identify the common and significant determinants of hypovitaminosis D.

METHODS

Six regions of the world were reviewed-Asia, Europe, Middle East and Africa, Latin America, North America, and Oceania-through a survey of published literature.

RESULTS

The definition of vitamin D insufficiency and deficiency, as well as assay methodology for 25-hydroxyvitamin D or 25(OH)D, vary between studies. However, serum 25(OH)D levels below 75 nmol/L are prevalent in every region studied whilst levels below 25 nmol/L are most common in regions such as South Asia and the Middle East. Older age, female sex, higher latitude, winter season, darker skin pigmentation, less sunlight exposure, dietary habits, and absence of vitamin D fortification are the main factors that are significantly associated with lower 25(OH)D levels.

CONCLUSION

Reports from across the world indicate that hypovitaminosis D is widespread and is re-emerging as a major health problem globally.

Effects of human aging on periodontal tissues

Loss of teeth is frequently associated with periodontal disease in older adults. The aim of this review was to present the effects of aging on the periodontal tissues. Aging alone does not lead to critical loss of periodontal attachment in healthy elderly persons. The effects of aging on periodontal tissues are based on molecular changes in the periodontal cells, which intensify bone loss in elderly patients with periodontitis. These effects may be associated with (1) alterations in differentiation and proliferation of osteoblasts and osteoclasts; (2) an increase in periodontal cell response to the oral microbiota and mechanical stress leading to the secretion of cytokines involved in osseous resorption; and (3) systemic endocrine alterations in the elderly people.

Is this D vitamin to worry about? Vitamin D insufficiency in an inpatient sample

OBJECTIVE

The aim of the present study was to investigate the relationship between reduced serum vitamin D levels and psychiatric illness.

METHOD

This study was an audit of serum 25-hydroxyvitamin D (25-OHD) levels measured routinely in a sample of 53 inpatients in a private psychiatric clinic. These levels were compared with those of controls without psychiatric illness.

RESULTS

The median levels of serum 25-OHD were 43.0 nmol L(-1) (range 20-102 nmol L(-1)) in the patient population, 46.0 nmol L(-1) (range 20-102 nmol L(-1)) in female patients (n =33) and 41.5 nmol L(-1) (range 22-97 nmol L(-1)) in male patients (n =20). The proportion of vitamin D insufficiency (serum 25-OHD < or =50 nmol L(-1)) in this patient population was 58%. Furthermore, 11% had moderate deficiency (serum 25-OHD < or =25 nmol L(-1)). There was a 29% difference between mean levels in the patient population and control sample (geometric mean age- and season-adjusted levels: 46.4 nmol L(-1) (95% confidence interval (CI) =38.6-54.9 nmol L(-1)) vs 65.3 nmol L(-1) (95%CI =63.2-67.4 nmol L(-1)), p <0.001).

CONCLUSION

Low levels of serum 25-OHD were found in this patient population. These data add to the literature suggesting an association between vitamin D insufficiency and psychiatric illness, and suggest that routine monitoring of vitamin D levels may be of benefit given the high yield of clinically relevant findings.

Vitamin D deficiency in general medical inpatients in summer and winter

BACKGROUND

Vitamin D deficiency is common in various populations worldwide. Adverse effects of vitamin D deficiency are the development of bone disorders; however, other diseases such as multiple sclerosis, type 1 diabetes, rheumatoid arthritis and certain cancers have also been linked to vitamin D deficiency. The general medical inpatient population is a group at increased risk of vitamin D deficiency. These patients often have coexistent risk factors for its consequences. This study aims to document a point prevalence of vitamin D deficiency in this population.

METHODS

Two cross-sectional audits of patients admitted to general medicine units were carried out--the first in mid-November at the end of winter and the second in mid-April and May at the end of summer. Information regarding patients' comorbidities, medication usage, previous falls and fractures was obtained and serum 25-hydroxyvitamin D, parathyroid hormone and calcium levels were measured.

RESULTS

A total of 129 patients was studied (65 in winter and 64 in summer). Ninety-four patients (74%) had 25-hydroxyvitamin D levels < or = 50 nmol/L. Seven patients had severe deficiency (levels < or = 12.5 nmol/L). Average vitamin D levels were lower at the end of winter (35 vs 43 nmol/L, P = 0.007). Of the 37 patients receiving vitamin D supplements, 20 (54%) had 25-hydroxyvitamin D levels < or = 50 nmol/L.

CONCLUSION

Low vitamin D levels were common in this general medical inpatient population. The average vitamin D level was lower in the patient group tested in November following winter. Supplementation of vitamin D did not uniformly prevent deficiency.

The association between non-melanoma skin cancer and osteoporotic fractures--a population-based record linkage study

We studied the association between osteoporotic fractures and prior non-melanoma skin cancer (NMSC, a biomarker for cumulative sun exposure). The risk of prior NMSC in our fracture cohort was significantly reduced (standardised incidence ratio 0.69, 95% CI 0.61, 0.78). Adequate lifetime sun exposure may be necessary to protect against osteoporotic fractures in later life.

INTRODUCTION

The relationship between cumulative sun exposure and osteoporotic fractures is uncertain. We aimed to study the association between non-melanoma skin cancer (NMSC), a marker of cumulative sun exposure, and osteoporotic fractures in an older cohort.

METHODS

A retrospective cohort study in southern Tasmania in people aged at least 50 years with incident radiographic fracture (n = 2,283) was carried out. By record linkage to the Tasmanian Cancer Registry the cohort was followed backwards through time until the occurrence of NMSC or end-of follow-up. Relative risk was estimated by the standardised incidence ratio (SIR) using sex-, age- and calendar year-specific cancer incidence rates in southern Tasmania as reference.

RESULTS

The incidence of prior NMSC in the fracture cohort was 31% lower than for the general population (SIR 0.69, 95% CI 0.61, 0.78). This effect was significant for most fracture subtypes except pelvic and wrist fractures and observed for both NMSC subtypes, squamous cell carcinoma and basal cell carcinoma.

CONCLUSIONS

Older people with osteoporotic fractures may have had lifestyles linked to lower cumulative sunlight exposure. Achieving a balance between adequate lifetime sun exposure and protection against its adverse effects (such as fractures and skin cancer) may require assessment of individual risks.

Vitamin D deficiency may play a role in depression

Vitamin D is known to be widely deficient in Western populations. The implications of this in terms of bone health are increasingly understood, yet its impact on other health areas, particularly mental health, is unclear. Recent data suggests that hypovitaminosis D may be common, especially in the elderly. Other studies have suggested that low levels of vitamin D are associated with poor mood. There are a number of trials that have suggested a role for Vitamin D in the supplementary treatment of depression. Dose may be a critical issue, as sun exposure and dietary intake may be low and high doses may be required.

High prevalence of secondary hyperparathyroidism due to hypovitaminosis D in hospitalized elderly with and without hip fracture

OBJECTIVES

To determine and compare the prevalence of secondary hyperparathyroidism (HPTH) in a population of community-dwelling and institutionalized older adults hospitalized with and without hip fracture, and to evaluate factors correlated with secondary HPTH in this population.

METHODS

Circulating concentrations of serum intact PTH, 25-hydroxyvitamin D [25(OH)D] total serum calcium and albumin were measured in 160 subjects with an osteoporotic fracture of the proximal femur and in 160 matched controls hospitalized for a disease unrelated to bone status. Patients with secondary causes of bone loss and taking medications affecting bone metabolism were excluded. Age, sex, place of residence and the ability to perform basic activities of daily living (BADL) two weeks before hospital admission were recorded at baseline.

RESULTS

Patients were comparable with regard to the baseline demographic, biochemical and functional characteristics. The overall prevalence of secondary hyperparathyroidism was 51.2%, without significant differences between hip fractured patients and controls (50.6 vs 51.9%, p=0.911). In bivariate analysis only the age and functional status (BADL) demonstrated a significant relationship with secondary HPTH, while sex and place of residence were not significant. These results were also confirmed in multivariate analysis. Particularly, the risk of secondary HPTH increased with age and with the number of functions lost in BADL: patients fully dependent showed a 3 times as high risk (odd ratio 3.07, 95% confidence interval 1.73 to 5.46, p=0.000) compared to patients independent in BADL, and subject aged >88 yr had a twice as high risk of developing secondary HPTH compared to younger ones (odd ratio 2.28, 95% confidence interval 1.20 to 4.32, p=0.012).

CONCLUSION

These results show that secondary HPTH due to hypovitaminosis D is a frequent disorder in hospitalized elderly, strongly correlated with the functional status, irrespective of sex and place of residence.

Vitamin D insufficiency in older female community-dwelling acute hospital admissions and the response to supplementation

OBJECTIVES

A significant proportion of the older population may exhibit vitamin D insufficiency. We sought to establish the proportion of 25-hydroxyvitamin D (25OHD) insufficient individuals in an older female cohort presenting for acute medical admission and how they responded to supplementation.

DESIGN

A prospective cohort study.

SETTING

Hospital admissions followed up as a population-based study.

SUBJECTS

A total of 114 consecutive female acute medical admissions aged over 65 years from November 2003 to January 2004 were enrolled. All admissions with hypercalcaemia, metabolic bone disease (other than osteoporosis/osteomalacia) and creatinine > 150 micromol/l were excluded.

INTERVENTIONS

iPTH, calcium and 25OHD levels were measured in each patient. Of the total, 22 were already receiving calcium and vitamin D supplementation at enrolment. The remaining 92 were commenced on 800 IU of vitamin D and 1 g calcium, and levels were reassessed after supplementation for 3 months.

RESULTS

25-Hydroxyvitamin D insufficiency, as defined by a 25OHD concentration of < 50 nmol/l, was present in 86 (75.4%) patients at initial assessment (mean 35.8 nmol/l, s.d. 23.3). Secondary hyperparathyroidism was present in only 36.7% of those with 25OHD deficiency at baseline. Of the total, 51 (44.7%) patients presented for follow-up. 25-Hydroxyvitamin D concentration increased in this group from 42.1 nmol/l (s.d. 26.6) to 59.5 nmol/l (s.d. 27.4) after supplementation, P < 0.001, but 18(35.3%) still remained deficient. There was no significant change in iPTH or calcium following supplementation. Assessment of compliance revealed 6 (11.7%) admitted to partial or non-compliance.

CONCLUSIONS

Insufficiency of 25OHD was very common in this cohort. Despite calcium and vitamin D supplementation, 25OHD concentrations failed to reach normality in a significant proportion. Maintaining vitamin D and calcium intake at the level of current recommended doses may not be sufficient to ensure adequate 25OHD stores.

Influence of ultraviolet radiation on the production of 25 hydroxyvitamin D in the elderly population in the city of São Paulo (23 degrees 34'S), Brazil

The lack of vitamin D is a major changeable factor involved in the pathophysiology of osteoporosis. Since the major source for this hormone is its cutaneous synthesis via ultraviolet radiation (UVR), we studied the serum level of 25-hydroxyvitamin D (25OHD) in 250 free-living elderly people (79.1 years old) from a subtropical region according to the UVR incidence and its correlations with parathormone (PTH) and ionized calcium. UVR and 25OHD differed according to the season of the year (P<0.001), with greater radiation in the summer and less in the winter, whereas the 25OHD peak and nadir occurred in autumn and spring, respectively. The highest 25OHD mean was 67.2 nmol/l, and the lowest was 29.1 nmol/l corresponding, respectively, to the measure of the month subsequent to the one of most and least sunlight incidence. Clustered by season, the correlation between UVR and 25OHD for the following seasons was r=0.98 and between the PTH and 25OHD of corresponding seasons, r=-0.95. Vitamin D deficiency occurred in 15.4% of patients, insufficiency in 41.9% and secondary hyperparathyroidism in 55%. In conclusion, we found a seasonal variation in 25OHD levels that strongly correlated with the PTH levels when separated by the seasons of the year. The 25OHD levels correlated with the UVR of the previous quarter, requiring no less than 30 days for serum changes arising from exposure to or deprivation of UVR to be observed. The prevalence of vitamin D deficiency/insufficiency found was greater than expected, even when compared to countries exposed to less solar irradiation. Thus, measures to encourage greater sun exposure and food enrichment policies should also be considered.

Vitamin D: More than just affecting calcium and bone

Vitamin D is a fat-soluble steroid that is essential for maintaining normal calcium metabolism. In vitamin D deficiency, calcium absorption is insufficient and cannot satisfy the body's needs. Consequently, parathyroid hormone production increases and calcium is mobilized from bones and reabsorbed in the kidneys to maintain normal serum calcium levels--a condition defined as secondary hyperparathyroidism. Most organs, including the gut, brain, heart, pancreas, skin, kidneys, and immune system have receptors for 1,25 (OH)vitamin D. Furthermore, all of these organs have the capacity to synthesize 1,25 (OH)vitamin D from vitamin D. Extensive research suggests that vitamin D deficiency is common and represents a global health problem. Clinical consequences related to low vitamin D levels include not only osteomalacia, osteoporosis, and rickets, but also neuro-muscular dysfunction and fractures. Falls related to neuromuscular dysfunction lead to 40% of all nursing home admissions and are the largest single cause of injury-related deaths in elderly people. About one-third of all persons 65 and older fall at least once a year, resulting in more than 1.5 million emergency room treatments and more than 300,000 hospitalizations. Falls cause more than 11,000 deaths per year, most of them in elderly patients (> or = 75 years) who suffer hip fractures. It is well established that vitamin D deficiency not only has serious consequences for bone health, but also for other organ systems. Previous studies have shown that vitamin D supplementation reduces the number of fractures and directly improves neuromuscular function, thus helping to prevent falls and subsequent fractures. In addition, vitamin D appears to have other important functions as a regulator of cell differentiation and cell growth.

Calcium metabolism in the frail elderly

Elderly residents of aged care facilities are usually considered at high risk of osteoporosis not only due to their age, but also due to nutritional factors, poor sunlight exposure and renal insufficiency. This study aimed to describe calcium metabolism and related hormones in this high-risk population. A total of 1280 elderly residents of hostels and nursing homes in the northern Sydney area (aged 65 years or over) had serum analysis for clinical chemistry including serum 25-hydroxy vitamin D (25OHD) and parathyroid hormone (PTH). Moderate renal impairment (creatinine clearance 30-60 ml/min) was common (62%), but hypocalcaemia was uncommon (7.0%). Mild hypoalbuminaemia was common (34% below 40 g/l, but only 3.2% below 35 g/l); 77.5% of the cohort had low serum 25OHD levels (<39 nmol/l) and 41.7% had elevated PTH levels (>66 pg/ml). Independent predictors of low serum 25OHD levels included gender, age, serum PTH, season, mobility and creatinine clearance. Use of vitamin D supplementation conferred modestly higher serum 25OHD levels (45.5 vs 27.1 nmol/l in non-supplemented residents, p < 0.0001) and lower PTH levels (50.0 vs 78.1 pg/ml, p < 0.0001). Despite adequate overall nutrition, vitamin D deficiency is present in the majority of this population. Vitamin D deficiency remains a significant public health problem in the institutionalized frail elderly. Currently available supplements are not adequate or utilized frequently enough to address this problem.

Vitamin D insufficiency in adolescent males in Southern Tasmania: prevalence, determinants, and relationship to bone turnover markers

There are limited data on vitamin D insufficiency in healthy children. The aim of this study was to describe the prevalence and determinants of vitamin D insufficiency and its association with bone turnover in adolescent boys (N = 136, mean age 16 years). Sun exposure and physical activity were assessed by questionnaire. Vitamin D stores were assessed by serum 25-hydroxyvitamin D3 (25[OH]D3). Bone turnover was assessed by bone-specific alkaline phosphatase (BAP) and urinary pyridinoline (PYR) to creatinine (Cr) ratio (mmol PYR/micromol Cr). The mean 25(OH)D3 level was low (44 nmol/l; 68% < 50 nmol/l; range, 16-87) and was associated with self-reported sun exposure on winter weekends (r = 0.23, p = 0.01), school holidays (r = 0.22, p = 0.01), and weekdays (r = 0.17, p = 0.05). It was also associated with number of sports (r = 0.34, p < 0.001) and vigorous activity (r = 0.22, p = 0.01) but not television, computer, and video watching (r = -0.04, p = 0.68). In multivariate analysis, number of sports but not total sun exposure remained significantly associated with 25(OH)D3. Furthermore, 25(OH)D3 was significantly associated with BAP in cutpoint analysis (cutpoint 55 nmol/l, p = 0.03) but not continuous analysis (r = -0.12, p = 0.16) and PYR in both forms (r = -0.23, p = 0.01, cutpoint 43 nmol/l, p = 0.01). In conclusion, vitamin D insufficiency is common in healthy adolescent boys in winter in our setting, is primarily derived from sports-related sun exposure, and is associated with bone turnover markers. These data suggest that a 25(OH)D3 level of at least 43-55 nmol/l is required for optimal bone health in children.

Vitamin D and adult bone health in Australia and New Zealand: a position statement

A significant number of Australians are deficient in vitamin D--it is a fallacy that Australians receive adequate vitamin D from casual exposure to sunlight. People at high risk of vitamin D deficiency include elderly people (particularly those in residential care), people with skin conditions where avoidance of sunlight is advised, those with dark skin (particularly if veiled), and those with malabsorption. Exposure of hands, face and arms to one-third of a minimal erythemal dose (MED) of sunlight (the amount that produces a faint redness of skin) most days is recommended for adequate endogenous vitamin D synthesis. However, deliberate sun exposure between 10:00 and 14:00 in summer (11:00-15:00 daylight saving time) is not advised. If this sun exposure is not possible, then a vitamin D supplement of at least 400 IU (10 microg) per day is recommended. In vitamin D deficiency, supplementation with 3000-5000 IU ergocalciferol per day (Ostelin [Boots]; 3-5 capsules per day) for 6-12 weeks is recommended. Larger-dose preparations of ergocalciferol or cholecalciferol are available in New Zealand, Asia and the United States and would be useful in Australia to treat moderate to severe vitamin D deficiency states in the elderly and those with poor absorption; one or two annual intramuscular doses of 300 000 IU of cholecalciferol have been shown to reverse vitamin D deficiency states.

Associations with Vitamin D deficiency in "at risk" Australians

In a study of 185 elderly living in assisted care and 192 frail aged living in the community in the Sydney metropolitan area, nursing home residents were found to be at a 3-fold and hostel dwellers at a 2-fold risk of Vitamin D [25(OH)D] deficiency (<25 nmol/L) compared to self care residents. Middle Eastern people were found to be at 4-fold risk and Vietnamese a 3-fold risk of deficiency compared to their Australian counterparts. In recently arrived Chinese immigrants, Vitamin D deficiency, was found in 28%, and marginal levels (<37 nmol/L) in 60%, compared to the 34 and 76% found in our nursing home population, and 25 and 57% in hostel care residents. Of the Middle Eastern elderly, 58% were deficient and 83% marginal; although only 18% of Vietnamese were deficient, 68% had marginal Vitamin D status. Other factors associated with Vitamin D deficiency were mobility and sun exposure in assisted care, and low dietary Vitamin D and calcium intake, reduced exercise levels and high % body fat levels in the immigrant groups.

High prevalence of vitamin D insufficiency in healthy elderly people living at home in Argentina

OBJECTIVE

To evaluate the nutritional status of vitamin D in urban populations of healthy elderly people living at home, in different regions of Argentina.

DESIGN

Cross-sectional study.

SUBJECTS

In total, 386 ambulatory subjects over 65 y of age from seven cities (between latitude 26 degrees S and 55 degrees S) were asked to participate between the end of winter and the beginning of spring. Of these, 369 accepted, 30 were excluded because of medical history or abnormal biochemical determinations. Finally, 339 subjects (226 women and 113 men) (X+/-s.d.) (71.3+/- 5.2 y) were included.

RESULTS

Serum 25OHD levels were lowest in the South (latitude range: 41 degrees S-55 degrees S): 14.2+/-5.6 ng/ml (P<0.0001vs North and Mid regions); highest in the North (26 degrees S-27 degrees S): 20.7+/-7.4 ng/ml (P<0.03 vs Mid, P<0.0001vs South); and intermediate in the Mid region (33 degrees S-34 degrees S) 17.9+/-8.2 ng/ml. Serum mid-molecule PTH (mmPTH) and 25OHD were inversely related: (r=-0.24, P<0.001). A cutoff level of 25OHD at which serum mmPTH levels began to increase was established at 27 ng/ml. A high prevalence (87-52%) of subjects with 25OHD levels in the deficiency-insufficiency range (25OHD levels <20 ng/ml) was detected.

CONCLUSION

This study shows that vitamin D deficiency/insufficiency in the elderly is a worldwide problem. Correction of this deficit would have a positive impact on bone health of elderly people.

The Australian experience in sun protection and screening for melanoma

Australia has the world's highest incidence of skin cancer. Despite excellent prevention and early diagnosis education programs and an increasing percentage of the population with darker and more UV tolerant skins, skin cancer remains a major and expensive community medical problem. However, primary and secondary prevention programs are now showing positive outcomes, especially in melanoma incidence and survival. Primary and secondary prevention programs are conducted by a variety of non-government organizations such as the Australian Cancer Council, which is comprised of state anticancer groups, with some assistance from State and Federal health agencies. Current and future campaigns are becoming focused on specific community groups, noticeably teenagers and the older population. The role of sunscreens as the primary preventative approach has been superceded by sunlight avoidance campaigns. In light of an increasing rate of early diagnosis, a low and falling morbidity of melanoma, improving general practitioner competence in skin cancer diagnosis and proliferation of skin cancer clinics throughout Australia, it is unlikely a national skin cancer screening program will be implemented. Ozone depletion, a sunlight overloaded environment, increased leisure time and an outdoor lifestyle necessitate continued efforts to minimise the cost and morbidity of skin cancer in Australia.

Vitamin D deficiency is common and unrecognized among recently arrived adult immigrants from The Horn of Africa

The prevalence of and risk factors for vitamin D deficiency were examined for recent adult immigrants from East Africa living in Melbourne. Demographic data were collected via a face-to-face questionnaire and risk factors predicting deficiency were examined. Suboptimal levels <25 nmol/L were found in 61 patients (53%; 74% of women; 20% of men). Lower levels were more likely in: (i) patients with a longer duration of residence in Australia, (ii) patients who were mostly covered when outdoors and (iii) women. Routine assessment for vitamin D deficiency should be considered for male and female immigrants from East Africa.

Vitamin D status of women in the Geelong Osteoporosis Study: association with diet and casual exposure to sunlight

OBJECTIVE

To assess vitamin D intake and casual exposure to sunshine in relation to serum 25-hydroxyvitamin D (25OHD) levels.

DESIGN

Cross-sectional study of a population-based, random sample of women aged 20-92 years, assessed between 1994 and 1997.

SETTING AND PARTICIPANTS

861 women from the Barwon Statistical Division (population, 218000), which includes the city of Geelong (latitude 38 degrees south) in Victoria.

MAIN OUTCOME MEASURES

Vitamin D intake; serum 25OHD level; season of assessment; exposure to sunshine.

RESULTS

Median intake of vitamin D was 1.2 microg/day (range, 0.0-11.4 microg/day). Vitamin D supplements, taken by 7.9% of participants, increased intake by 8.1% to 1.3 microg/day (range, 0.0-101.2 microg/day) (P< 0.001). A dose-response relationship in serum 25OHD levels was observed for sunbathing frequency before and after adjusting for age (P< 0.05). During winter (May-October), serum 25OHD levels were dependent on vitamin D intake (partial r2= 0.01; P<0.05) and were lower than during summer (November-April) (age-adjusted mean, 59nmol/L [95% Cl, 57-62] v 81 nmol/L [95% CI, 78-84]; P<0.05). No association was detected between serum 25OHD and vitamin D intake during summer. The prevalences of low concentrations of serum 25OHD were, for <28nmol/L, 7.2% and 11.3% overall and in winter, respectively; and, for <50 nmol/L, 30.0% and 43.2% overall and in winter, respectively.

CONCLUSIONS

At latitude 38 degrees south, the contribution of vitamin D from dietary sources appears to be insignificant during summer. However, during winter vitamin D status is influenced by dietary intake. Australia has no recommended dietary intake (RDI) for vitamin D, in the belief that adequate vitamin D can be obtained from solar irradiation alone. Our results suggest that an RDI may be needed.