Monthly, High-Dose Vitamin D Supplements Found Not to Prevent Cancers

High Dose monthly Vitamin D supplements don’t seem protective against cancer, a JAMA Oncology study reports. Previous studies have found an inverse relationship between serum vitamin D levels and cancer risk, but supplementation hasn’t produced consistent results.

Researchers used data from a New Zealand study examining the effect of high-dose supplements on cardiovascular health. In their post hoc analysis they used national cancer registries to compare cancer incidence and mortality in roughly 5000 participants randomized to vitamin D (200,000 IU oral bolus plus monthly 100,000 IU) or placebo. Participants ranged in age from 50 to 84 and were recruited from Auckland family practices.

During their median 3.3-year participation, cancer incidence was almost identical in the two groups: 6.5% with vitamin D and 6.4% with placebo.

The authors wondered whether daily or weekly doses — or a longer duration of supplementation — would bring different results.


JAMA Oncology article (Free abstract)

Background: Physician’s First Watch coverage of vitamin D and lower colorectal cancer risk (Free)

Higher Omega-3 Intake May Not Provide CV Benefit

Increasing omega-3 intake doesn’t appear to reduce risk for heart disease, stroke, or mortality, according to a new Cochrane review.

Researchers examined 79 randomized, controlled trials that included over 110,000 participants with or without cardiovascular disease. Participants were randomized to receive either supplementation and/or clinician advice to increase intake of long-chain omega-3 polyunsaturated fatty acids or alpha-linolenic acid (ALA) or usual or reduced intake for at least 1 year. Most trials compared omega-3 capsules with placebo.

Omega 3s had little to no effect on mortality or adverse cardiovascular events. Increased intake of ALA, found in nuts and seeds, intake might slightly reduce risk for cardiovascular events, coronary mortality, and arrhythmias, but the authors estimate that 1000 people would need to increase their ALA intake to avert one cardiovascular event or coronary death.

They write: “In light of the evidence in this review it would be appropriate to review official recommendations supporting supplemental [omega-3] fatty acid intake.”


Cochrane review (Free abstract)

Background: Physician’s First Watch coverage of study showing no cardiovascular benefit of omega-3 intake(Free)

Antibiotics Commonly Prescribed Inappropriately in Urgent Care

Inappropriate antibiotic prescribing is common in ambulatory care settings, particularly urgent care, according to a JAMA Internal Medicine research letter.

Using an outpatient claims database, researchers tracked antibiotic prescriptions in various outpatient settings. Visits for antibiotic-inappropriate respiratory illness (e.g., suspected viral upper respiratory infection or pneumonia, bronchitis or bronchiolitis, asthma or allergy, influenza, nonsuppurative otitis media) made up roughly 17% of retail clinic and urgent care visits and roughly 6% of medical office and emergency department visits. Of those diagnosed with an antibiotic-inappropriate respiratory illness, here were the proportions prescribed antibiotics:

  • Urgent care: 46%
  • Emergency department: 25%
  • Medical offices: 17%
  • Retail clinics: 14%

Commentators note: “Unlike patients seen at an outpatient practice, those who go to an urgent care center are unlikely to see their regular physician or a member of their physician’s team. Primary care physicians may be in a better position than an unfamiliar clinician to convince patients that it is not in their interest to take an antibiotic.”


JAMA Internal Medicine research letter (Free)

JAMA Internal Medicine commentary (Free)

Background: NEJM Journal Watch General Medicine coverage of behavioral interventions to reduce inappropriate antibiotic prescribing (Your NEJM Journal Watch registration required)

Frequent Video Gaming and Chatting Tied to Risk for Subsequent ADHD Symptoms in Teens

Adolescents who engage in various digital media activities several times a day face increased risk for developing attention-deficit/hyperactivity disorder (ADHD) symptoms, suggests a longitudinal study in JAMA.

Nearly 2600 high school sophomores in Los Angeles without ADHD symptoms at baseline completed ADHD symptom assessments every 6 months for 24 months. They also reported their use of 14 different digital media activities (e.g., checking social media sites, playing video games alone, video chatting).

Roughly 6% of participants reported ADHD symptoms during any follow-up assessment. For every media activity that a participant engaged in several times a day, the odds of developing ADHD symptoms increased by 10%. In particular, ADHD symptoms developed in 5% of teens with no high-frequency media activity, but in nearly 10% of those with seven high-frequency media activities.

Based on this study, Dr. Jenny Radesky offers several new points of discussion for parents and teens in NEJM Journal Watch Pediatrics and Adolescent Medicine. See the linked summary below.


JAMA article (Free abstract)

NEJM Journal Watch Pediatrics and Adolescent Medicine summary of this study (Your NEJM Journal Watch subscription required)

Background: NEJM Journal Watch Pediatrics and Adolescent Medicine coverage of digital media use and mental health in teens (Your NEJM Journal Watch registration required)

Low-Dose Aspirin Ineffective in Heavier Patients?

Low-dose aspirin may not be effective in preventing cardiovascular events in people weighing 70 kg (154 pounds) or more, a Lancet study suggests.

Researchers analyzed 10 trials that evaluated aspirin versus controls for primary prevention of cardiovascular events in 120,000 people.

Daily, low-dose aspirin (75–100 mg) was associated with reduced risk for cardiovascular events among those weighing less than 70 kg (odds ratio, 0.77), but there was no significant effect for heavier patients — roughly 80% of men in the study and nearly half of women weighed 70 kg or more. In the heavier group, low-dose aspirin may be even less effective in smokers and in those who take enteric-coated aspirin.

High-dose aspirin (300–325 or 500 mg), meanwhile, appeared to be effective in reducing primary cardiovascular events only patients weighing 70 kg or more (OR, 0.79).

Commentators said that people with more body mass may have more esterases, which clear aspirin and would reduce the bioavailability of the drug.

The authors conclude: “A one-dose-fits-all approach to aspirin is unlikely to be optimal, and a more tailored strategy is required.


Lancet article (Free)

Lancet comment (Free)

Background: NEJM Journal Watch Cardiology coverage of antiplatelet activity of enteric-coated aspirin



ASPIRIN- to take or not to take 

The latest recommendation from the US preventive task force is to take aspirin (low dose) to prevent both heart disease and colon cancer in adults aged 50-59, who have significant risk factors.

The guidelines are published in the Annals of Internal Medicine:

  • Low-dose aspirin is recommended for adults aged 50–59 who have at least a 10% risk for a cardiovascular event in the next decade, low bleeding risk, and a life expectancy of at least 10 years; patients must also be willing to take aspirin daily for at least 10 years.
  • For adults aged 60–69 fitting the above criteria, the decision to start aspirin should be an individual one.
  • For patients younger than 50 and older than 69, there is not enough evidence to make recommendations.