With Comments from Russell H. Greenfield, MD
Dr. Greenfield is Medical Director, Carolinas Integrative Health, Carolinas HealthCare System, Charlotte, NC, and Clinical Assistant Professor, School of Medicine, University of North Carolina, Chapel Hill, NC.
Calcium and Vitamin D Supplementation to Prevent Fractures
Source: Porthouse J, et al. Randomised controlled trial of calcium and supplementation with cholecalciferol (vitamin D3) for prevention of fractures in primary care. BMJ 2005;330:1003.
Goal: To assess whether supplementing with calcium and vitamin D in older women at risk for hip fracture reduces fracture rates.
Design: Pragmatic open, randomized controlled trial performed in primary care settings.
Subjects: More than 3,000 community-dwelling women older than age 70 with at least one risk factor for fracture.
Methods: Participants were randomized to receive either 1,000 mg calcium carbonate plus 800 IU cholecalciferol together with an information leaflet on dietary calcium intake and fall prevention, or just the leaflet alone. Self-reported calcium intake was defined by answers to a brief 10-item questionnaire. Outcome measures included any clinical fracture, hip fractures specifically, falls, quality of life (SF-12 and EuroQOL), and compliance. Outcome data were primarily obtained from questionnaires sent to participants every six months, but also through physician contact.
Results: With a median follow-up of 25 months, clinical fracture rates were lower than expected in both groups, but not significantly different. No differences were identified between groups regarding incidence of falls or quality of life.
Conclusion: There is no significant benefit from supplementing with calcium and vitamin D as relates to preventing falls or fractures in community-dwelling older women with one or more risk factors for hip fracture.
Study strengths: Large sample size; pragmatic design allows for increased generalizability.
Study weaknesses: Rate of adherence to protocol only 63%, even as measured through self-report; results do not apply to men; dose and type of calcium employed could have been optimized.
Of note: A pilot trial was performed in 1999 before the main trial began in 2001; this study employed calcium carbonate, although some practitioners believe that calcium citrate is better absorbed in the elderly, who typically possess lower levels of stomach acid; planned sample size was changed during the trial; patients did not receive magnesium; population at the center of this trial was relatively healthy and living independently as opposed to other calcium/vitamin D studies.
We knew that: Risk factors for hip fracture include any previous fracture, low body weight, smoking, family history of hip fracture, and poor health by self-report; the age-specific rate of hip fractures appears to be increasing; an earlier systematic review reported that supplemental vitamin D could reduce falls by more than 20%; patients in residential care and/or with dementia are at higher risk for fracture; results of prior investigations evaluating institutionalized elderly patients, who may be at greater risk of low calcium and vitamin D intake, suggested that calcium and vitamin D supplementation may help prevent some fractures; only one of four published large randomized trials evaluating vitamin D has shown benefit for reducing fractures.
Clinical import: The results of this study raised the eyebrows of many who routinely recommend the use of calcium and vitamin D to help treat osteoporosis, but it would be naïve to believe that calcium/vitamin D alone could adequately treat already weakened bones. Weight-bearing exercise and bone-active drugs are effective interventions in this regard. Primary prevention remains the ulti-mate goal, and adequate calcium and vitamin D intake, whether from diet or supplementation, is still widely considered to play an essential role in reducing the incidence of osteoporosis. Dosage may also be important, as most providers recommend calcium intakes for women of 1,200-1,500 mg/d as opposed to the 1,000 mg dose employed in this study. A lesser amount of magnesium is often suggested as well. Though this reviewer does not typically recommend preventive calcium supplementation for men due to concerns about prostate cancer, there are other benefits ascribed to calcium (prevention of colon polyps) and vitamin D (anticancer actions and perhaps a beneficial role in multiple sclerosis) not addressed by this study. These data raise important questions, but alone are insufficient cause to discontinue calcium/vitamin D supplementation.
What to do with this article: Keep a copy on your computer.
Fish Oils for Developmental Disorder
Source: Richardson AJ, et al. The Oxford-Durham Study: A randomized, controlled trial of dietary supplementation with fatty acids in children with developmental coordination disorder. Pediatrics 2005;115: 1360-1366.
Goal: To assess the effects of dietary supplementation with omega-3 and omega-6 fatty acids on children with developmental coordination disorder (DCD).
Study design: Pragmatic randomized, double-blind, placebo-controlled, parallel-group trial using a one-way crossover.
Subjects: British children with DCD (n = 117, aged 5-12 years, 78 boys) drawn from the first 12 general schools in one geographic region willing to assist with the study (potential subjects were identified by teachers at those schools).
Methods: Participants were randomized to receive either placebo capsules containing olive oil or a supplement containing 80% fish oil (558 mg eicosapentaenoic acid [EPA] plus 174 mg docosahexaenoic acid [DHA]) and 20% evening primrose oil. Teachers administered the capsules on school days and parents were responsible for maintaining study protocol over weekends. Parallel-group treatment took place for three months and was followed by a one-way crossover from placebo to active intervention for an additional three months. Primary outcomes were results on standardized, age-adjusted measures of motor and literacy skills, and teacher-rated changes in behavioral and learning problems (ADHD-related symptoms). Data were collected at baseline, three months, and six months.
Results: No effect of fish oil supplementation on motor skills was apparent at trial’s end; however, significant improvements were noted in spelling, reading, and behavior during the parallel-treatment phase for those who received fatty acid supplements. After one-way crossover, similar improvements were noted in the children who had initially received placebo.
Conclusion: For children with DCD, fatty acid supplementation may be an effective intervention to address cognitive and behavioral challenges, but not motor problems.
Study strengths: Intention-to-treat analysis with last observation carried forward; compliance established by cross-checking capsule counts with teacher logbooks; relatively high compliance rates (> 85%).
Study weaknesses: Sample size; selective recruitment that limits generalizability (a total of 1,782 children were suspected of having DCD-type challenges in a region encompassing 247 schools, but only 12 centers participated; those centers may have had more resources available to help children with developmental disorders); potential bias related to teachers being involved in recruitment of subjects, administration of capsules, and subsequent evaluations; no parental logbooks to determine compliance with protocol on weekends; no breakdown in response by age (did younger children respond better than older ones?); short duration.
Of note: DCD affects about 5% of children to a serious degree and involves specific motor function impairment as well as substantial symptom overlap with ADHD, dyslexia, and autistic spectrum disorders; children with DCD typically have difficulty with written language, organizational skills, attention and behavior; no randomized controlled trials of fatty acid supplementation for autism have yet been published; participants were not receiving any other form of treatment for DCD; the fatty acid dosage employed in this study required ingestion of 2 capsules taken three times daily, and yielded a very high intake of EPA:DHA; no adverse events were reported.
We knew that: Data suggest that fatty acid imbalances or deficiencies contribute to common childhood neurodevelopmental disorders with overlapping symptoms (including ADHD, autistic spectrum disorders, dyspraxia, and dyslexia), but results from the few human randomized trials using fatty acids have been mixed; there is no established treatment for children with DCD; the optimal dosage and combination of fatty acids for supplementation in children is unknown.
Comments: It is compelling, if not surprising, that short-term administration (three months) of essential fatty acids could lead to such significant improvements in cognition and behavior in a childhood developmental disorder. The study results need to be corroborated in subsequent trials, as the findings are not easily generalizable. Likewise, more data are needed to identify the proper dose of EPA and/or DHA, and to solidify or refute the stance that if fatty acid supplementation is to be employed for children, therapy should be initiated as soon as possible in life to afford the greatest clinical benefit. These cautions aside, considering specific childhood developmental disorders and the paucity of effective treatments for them, a trial of fish oil supplementation seems warranted as both a safe and potentially effective intervention.
What to do with this article: Keep a hard copy in your file cabinet.
Greenfield RH. Calcium and vitamin D supplementation to prevent fractures. Altern Med Alert 2005;8(7):83-84.
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