134 resultados para Vitamin D deficiency
em Deakin Research Online - Australia
Resumo:
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.
Resumo:
Background: Vitamin D deficiency is common. Recently Roche Diagnostics removed their Elecsys Vitamin D3 (25OH) electrochemiluminescence immunoassay (ECLIA) from use, citing deteriorating traceability to the reference method (liquid chromatography tandem mass spectrometry; LCMSMS). We investigated the performance of the Roche assay (2 assay formulations) against an LCMSMS method and the widely used DiaSorin radioimmunoassay (RIA) method.
Methods: Two sets of samples from separate populations were assayed for vitamin D. The first set was assayed using three different methods: RIA (DiaSorin) in 2004, polyclonal ECLIA (Roche) in early 2009 and LCMSMS in early 2010. The second set was assayed using polyclonal and monoclonal ECLIA (Roche) and LCMSMS in mid-2010.
Results: The correlation of the polyclonal ECLIA with the RIA was poor (ECLIA = 0.45 x RIA + 19, r2 = 0.59, n = 773). LCMSMS results correlated with RIA (RIA = 0.86 x LCMSMS + 4, r2 = 0.69, n = 49) better than with polyclonal ECLIA (polyclonal ECLIA = 0.55 x LCMSMS + 6, r2 = 0.62, n = 55) despite a storage interval of 6 years.
In recently collected samples monoclonal and polyclonal immunoassays gave similar results (monoclonal ECLIA = 0.93 polyclonal ECLIA -3, r2 = 0.60, n = 153). The correlation between monoclonal Roche ECLIA and LCMSMS in these samples was very poor (monoclonal ECLIA = 0.31 x LCMSMS + 23, r2 = 0.27).
Conclusions: At the time of its removal from the market, the Roche Elecsys Vitamin D3 (25OH) assay showed unacceptable performance, underestimating vitamin D levels. It seems that this bias preceded the introduction of the monoclonal assay. The worldwide distribution of the assay and the duration of this bias likely led to a significant number of patients starting supplementation unnecessarily.
Resumo:
• Vitamin D deficiency has re-emerged as a significant paediatric health issue, with complications including hypocalcaemic seizures, rickets, limb pain and fracture.
• A major risk factor for infants is maternal vitamin D deficiency. For older infants and children, risk factors include dark skin colour, cultural practices, prolonged breastfeeding, restricted sun exposure and certain medical conditions.
• To prevent vitamin D deficiency in infants, pregnant women, especially those who are dark-skinned or veiled, should be screened and treated for vitamin D deficiency, and breastfed infants of dark-skinned or veiled women should be supplemented with vitamin D for the first 12 months of life.
• Regular sunlight exposure can prevent vitamin D deficiency, but the safe exposure time for children is unknown.
• To prevent vitamin D deficiency, at-risk children should receive 400 IU vitamin D daily; if compliance is poor, an annual dose of 150 000 IU may be considered.
• Treatment of vitamin D deficiency involves giving ergocalciferol or cholecalciferol for 3 months (1000 IU/day if < 1 month of age; 3000 IU/ day if 1-12 months of age; 5000 IU/day if > 12 months of age).
• High-dose bolus therapy (300 000-500 000 IU) should be considered for children over 12 months of age if compliance or absorption issues are suspected.
Resumo:
Objective Vitamin D deficiency is recognized as a global public health problem, but the population-based prevalence of deficiency and its determinants in Australian adults is not known. This study evaluated the vitamin D status of Australian adults aged ≥25 years and risk factors associated with vitamin D deficiency in this population.
Design and Patients We studied a national sample of 11 247 Australian adults enrolled in the 1999/2000 Australian Diabetes, Obesity and Lifestyle (AusDiab) study drawn from 42 randomly selected districts throughout Australia.
Measurements Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by immunoassay. Vitamin D deficiency was defined as a concentration <50 nmol/l. Information on demographic and lifestyle factors was derived from interview-administered questionnaires.
Results The mean serum 25(OH)D concentration was 63 nmol/l (95% CI: 59–67 nmol/l). Only 4% of the population had a level <25 nmol/l, but the prevalence of vitamin D deficiency (<50 nmol/l) was 31% (22% men; 39% women); 73% had levels <75 nmol/l. The prevalence of vitamin D deficiency increased significantly with age, was greater in women, in those of non-Europid origin, in the obese and those who were physically inactive and with a higher level of education. Deficiency was also more common during winter and in people residing in southern Australia (latitude >35°S); 42% of women and 27% of men were deficient during summer–autumn, which increased to 58% and 35%, respectively, during winter–spring.
Conclusion Vitamin D deficiency is common in Australia affecting nearly one-third of adults aged ≥25 years. This indicates that strategies are needed at the population level to improve vitamin D status of Australians.
Resumo:
The main source of vitamin D for Australians is exposure to sunlight. Thus, levels of serum 25-hydroxyvitamin D3, the indicator of vitamin D status, vary according to the season and are lower at the end of winter.
In Australia and New Zealand, the prevalence of vitamin D deficiency varies, but is acknowledged to be much higher than previously thought. One study found marginal deficiency in 23% of women, and another frank deficiency in 80% of dark-skinned and veiled women. The groups at greatest risk of vitamin D deficiency in Australia are dark-skinned and veiled women (particularly in pregnancy), their infants, and older persons living in residential care.
Only a few foods (eg, fish with a high fat content) contain significant amounts of vitamin D. In Australia, margarine and some milk and milk products are currently fortified with vitamin D.
The average estimated dietary intake of vitamin D for men is 2.6–3.0 µg/day and for women is 2.0–2.2 µg/day. The estimated dietary requirement of vitamin D is at least 5.0 µg/day and may be higher for older people.
Adequate intake of vitamin D is unlikely to be achieved through dietary means, particularly in the groups at greatest risk, although vitamin D-fortified foods may assist in maintaining vitamin D status in the general population.
An appropriate health message for vitamin D needs to balance the need for sunshine against the risk of skin cancer.
Resumo:
BACKGROUND A significant number of Australians and people from specific groups within the community are suffering from vitamin D deficiency. It is no longer acceptable to assume that all people in Australia receive adequate vitamin D from casual exposure to sunlight.
OBJECTIVE This article provides information on causes, consequences, treatment and prevention of vitamin D deficiency in Australia.
DISCUSSION People at high risk of vitamin D deficiency include the elderly, those with skin conditions where avoidance of sunlight is required, dark skinned people (particularly women during pregnancy or if veiled) and patients with malabsorption, eg. coeliac disease. For most people, deficiency can be prevented by 5–15 minutes exposure of face and upper limbs to sunlight 4–6 times per week. If this is not possible then a vitamin D supplement of at least 400 IU* per day is recommended. In cases of established vitamin D deficiency, supplementation with 3000-5000 IU per day for at least 1 month is required to replete body stores. Increased availability of larger dose preparations of cholecalciferol would be a useful therapy in the case of severe deficiencies. * 40 IU (international units) = 1 µg
Resumo:
Objectives: To determine the prevalence of vitamin D deficiency in older people in residential care and the influence that the level of vitamin D may have on their incidence of falls.
Design: Prospective cohort.
Setting: Residential care facilities for older people in several states of Australia.
Participants: Six hundred sixty-seven women in low-level care and 952 women in high-level care, mean age 83.7 years.
Measurements: Serum 25-hydroxyvitamin D (25D) levels and recognized risk factors for falls including current medication use, a history of previous fractures, weight, tibial length (as a surrogate for height), cognitive function, walking ability, and frequency of going outdoors were determined. The women in low-level care and high-level care were followed for an average of 145 and 168 days, respectively. Falls were recorded prospectively in diaries completed monthly by residential care staff.
Results: Vitamin D deficiency (defined as a serum 25D level below 25 nmol/L) was present in 144 (22%) women in low-level care and 428 (45%) in high-level care. After excluding 358 bed-bound residents and adjusting for weight, cognitive status, psychotropic drug use, previous Colles fracture, and the presence of wandering behavior, log serum 25D level remained independently associated with time to first fall. The adjusted hazards ratio was 0.74 (95% confidence interval=0.59–0.94; P=.01), implying a 20% reduction in the risk of falling with a doubling of the vitamin D level.
Conclusion: Vitamin D deficiency is common in residential care in Australia. A low level of serum vitamin D is an independent predictor of incident falls.
Resumo:
Objective: To assess the vitamin D status of healthy young people living in Northern Ireland and the effect of vitamin D supplementation on vitamin D status and bone turnover.
Design: Double-blinded randomised controlled intervention study.
Setting: University of Ulster, Coleraine, Northern Ireland.
Subjects: In total, 30 apparently healthy students (15 male and 15 female subjects), aged 18–27 years, were recruited from the university, with 27 completing the intervention.
Interventions: Subjects were randomly assigned, to receive either 15 mug (600 IU) vitamin D3 and 1500 mg calcium/day (vitamin D group), or 1500 mg calcium/day (control group) for 8 weeks between January and March. Vitamin D status, bone turnover markers, serum calcium and parathyroid hormone concentrations were measured at baseline and post intervention.
Results: At baseline, vitamin D status was low in both the vitamin D group (47.9 (s.d. 16.0)) and the control group (55.5 (s.d. 18.6) nmol/l 25(OH)D). Post intervention vitamin D status was significantly higher in the vitamin D-treated group (86.5 (s.d. 24.5)) compared to the control group (48.3 (s.d. 16.8) nmol/l) (P<0.0001). There was no significant effect of supplementation on bone turnover markers or PTH concentrations.
Conclusions: This study suggests that young adults in Northern Ireland do not consume an adequate daily dietary intake of vitamin D to maintain plasma vitamin D concentrations in the wintertime. A daily supplement of 15 mug vitamin D3 significantly increased vitamin D status in these individuals to levels of sufficiency. Achievement of an optimum vitamin D status among young adults may have future positive health implications.
Resumo:
Vitamin D deficiency is associated with a myriad of musculoskeletal disorders in the elderly, including osteoporosis, reduced muscle function, falls and fractures. Recent scientific trials, conducted mostly in elderly or institutionalized women, indicate that supplementation with at least 800 IU/d of vitamin D3 or a dose required to raise serum 25(OH) D levels to at least 75 nmol/L, and approximately 1200 mg/d of calcium is most effective for improving many of these musculoskeletal and functional performance measures. While further targeted research is still needed in elderly men, vitamin D supplementation should be considered as a safe and low cost strategy to optimize musculoskeletal health and function in both elderly men and women.
Resumo:
Regular exercise, particularly progressive resistance training (PRT), is recognized as one of the most effective strategies to prevent age-related muscle loss (sarcopenia), but its effects on muscle function are mixed. However, emerging data indicates that high velocity PRT (fast concentric muscle contractions) is more effective for improving functional outcomes than traditional PRT. In terms of falls prevention, high-challenging balance training programs appear to be most effective. There is also compelling evidence that supplemental vitamin D is an effective therapeutic option for falls prevention. The findings from a recent meta-analysis revealed that supplemental vitamin D at a dose of at least 700–1,000 IU/d or an achieved serum 25(OH)D level of at least 60 nmol/L was associated with reduced falls risk among older individuals. Based on these findings, it is possible that the combination of exercise and vitamin D could have a synergistic effect on muscle morphology and function, particularly since both interventions have been shown to have beneficial effects on type II “fast twitch” muscle fibers and systemic inflammation, which have both been linked to losses in muscle mass and function. Unfortunately however, the findings from the limited number of factorial 2 × 2 design RCTs indicate that additional vitamin D does not enhance the effects of exercise on measures of muscle morphology, function or falls risk. However, none of these trials were adequately powered to detect a “synergistic” effect between the two treatment strategies, but it is likely that if an exercise-by-vitamin D interaction does exist, it may be limited to situations when vitamin D deficiency/insufficiency is corrected. Further targeted research in “high risk” groups is still needed to address this question, and evaluate whether there is a threshold level of serum 25(OH)D to maximize the effects of exercise on muscle and falls risk.
Resumo:
Objective : To assess the association between 25-hydroxyvitamin D (25[OH]D) status and obesity, cardiovascular diseases (CVDs), the metabolic syndrome, and type 2 diabetes mellitus (T2DM) in ethnic minorities.
Methods : Databases searched were CINHAL with full text, Global Health, MEDLINE with full text, and PsycINFO from 1980 through 2010 (February). Studies were included if they 1) targeted immigrants from low- to high-income countries or ethnic minorities, 2) focused primarily on 25(OH)D and its relation to obesity, T2DM, and/or CVDs, and 3) were published in peer-reviewed journals. The influences of key confounders such as age, gender, and ethnicity on any observed relations were also assessed. Due to the heterogeneity of study characteristics, only a narrative synthesis was undertaken.
Results : Ethnic minorities had significantly higher rates of vitamin D insufficiency (25[OH]D <50 nmol/L; children 43.6–48.7% versus 10%; adults 30.3–53% versus 13.7–26%) than their white counterparts. None of the studies reported a prevalence of obesity stratified by ethnicity. There was evidence supporting links between vitamin D deficiency and obesity-related chronic diseases, with 14 of 14 studies reporting a statistically significant result with a measurement of obesity, four of five for T2DM, four of five for CVDs, and one of one for the metabolic syndrome. However, the strength of the association varied across ethnic groups depending on the index used to measure adiposity, T2DM, and CVDs. Because most of the included studies were cross-sectional and there were variations in outcome measurements, it was not possible to determine the relative contributions of obesity or vitamin D insufficiency to CVD risk and risk of T2DM or which is the initial driver It is possible both have a role to play.
Conclusion : Further research specific to migrant populations using randomized controlled trials are required to establish whether causal links between 25(OH)D and obesity-related chronic disease exist, and whether vitamin D supplementation could be valuable in the prevention or treatment of obesity-related diseases.
Resumo:
• 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 400IU (10 μg) 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.
Resumo:
The prevalence of vitamin D deficiency varies, with the groups at greatest risk including housebound, community-dwelling older and/or disabled people, those in residential care, dark-skinned people (particularly those modestly dressed), and other people who regularly avoid sun exposure or work indoors.
Most adults are unlikely to obtain more than 5%–10% of their vitamin D requirement from dietary sources. The main source of vitamin D for people residing in Australia and New Zealand is exposure to sunlight.
A serum 25-hydroxyvitamin D (25-OHD) level of ≥ 50 nmol/L at the end of winter (10–20 nmol/L higher at the end of summer, to allow for seasonal decrease) is required for optimal musculoskeletal health.
Although it is likely that higher serum 25-OHD levels play a role in the prevention of some disease states, there is insufficient evidence from randomised controlled trials to recommend higher targets.
For moderately fair-skinned people, a walk with arms exposed for 6–7 minutes mid morning or mid afternoon in summer, and with as much bare skin exposed as feasible for 7–40 minutes (depending on latitude) at noon in winter, on most days, is likely to be helpful in maintaining adequate vitamin D levels in the body.
When sun exposure is minimal, vitamin D intake from dietary sources and supplementation of at least 600 IU (15 μg) per day for people aged ≤ 70 years and 800 IU (20 μg) per day for those aged > 70 years is recommended. People in high-risk groups may require higher doses.
There is good evidence that vitamin D plus calcium supplementation effectively reduces fractures and falls in older men and women.
Resumo:
The scientific literature related to vitamin D and bone health in older adults is extensive.
This article aims to summarise key practice points regarding vitamin D and bone health in older adults, relevant to general practitioners, and to provide an overview of the background literature to enable GPs to appreciate the extent of the supporting evidence.
Vitamin D supplementation can prevent falls, particularly in the vitamin D deficient elderly. However, adequate vitamin D levels and dietary calcium intake are needed for effective primary fracture prevention with greatest benefits occurring in the elderly with vitamin D deficiency and/or low dietary calcium intakes. For secondary fracture prevention, ie. preventing further fractures in the elderly who have already sustained a fragility fracture, specific anti-osteoporosis treatment is necessary. However, to maximise the benefits of these medications, vitamin D deficiency should be corrected and adequate dietary calcium consumed.
