Knowledge, attitudes and practices of Italian general practitioners on dietary supplements

A 2024 survey of 233 Italian general practitioners reveals that while most possess adequate knowledge and recognize their pivotal role in prescribing dietary supplements, a significant majority feel they lack sufficient training on the subject.

The Gist

Imagine your body as a high-performance car. You know you need good fuel (food) to run well. But what about the extra additives, the "turbo chargers," and the "special oils" you can buy at the gas station without a mechanic's note? These are dietary supplements (vitamins, minerals, protein powders, etc.).

This study is like a mechanic's report card. The researchers wanted to see how well Italian car mechanics (General Practitioners or GPs) understand these extra additives. Do they know which ones help the engine run smoother, and which ones might actually cause a breakdown?

Here is the story of what they found, broken down simply:

1. The Setup: Asking the Mechanics

The researchers sent a 62-question quiz to Italian doctors. Think of this quiz as a mix of:

• True/False questions: "Does too much protein hurt the kidneys?" (Like asking: "Does putting water in a gas tank ruin the engine?")
• Opinion questions: "Do you feel confident telling patients about these products?" (Like asking: "Do you feel ready to explain this to a customer?")

They got answers from 233 doctors. It wasn't a huge crowd (only about 3% of all Italian doctors responded), but it was enough to get a good snapshot.

2. The Results: The "Good News" and the "Bad News"

The Good News: The Mechanics Know the Basics
Most of the doctors (about 69%) passed the test with a "C" or better (scoring over 60%).

• They knew that too much of a good thing can be bad. For example, they correctly identified that dumping massive amounts of protein supplements can damage the kidneys.
• They understood that drugs and supplements can fight each other, like two people trying to steer the car in opposite directions.
• They agreed that patients should ask the doctor before taking these "additives." They see themselves as the captains of the ship, guiding the passengers.

The Bad News: The Mechanics Are Missing the Manual
Even though they passed the test, there were some scary gaps in their knowledge, like a mechanic who knows how to change a tire but doesn't know what the dashboard warning lights mean.

• Confusion on "Natural" vs. "Medicine": Only about 1 in 6 doctors realized that just because a supplement is "natural" doesn't mean it's free of toxic ingredients or hidden dangers.
• The "Magic Bullet" Myth: Many doctors didn't know that taking a multivitamin doesn't necessarily prevent cancer or heart disease. In fact, some studies suggest taking too many vitamins might actually be harmful.
• Specific Gaps: They were shaky on specific details, like exactly how much Vitamin D or Calcium an older person needs to prevent bone breaks.

3. The Attitude: "I Want to Help, But I Need More Training"

This is the most interesting part of the story.

• The Desire to Help: Almost every doctor (98%) said, "Yes, it is my job to talk to patients about these supplements." They know patients are buying them by the truckload, especially since the pandemic.
• The Feeling of Being Unprepared: Despite wanting to help, two-thirds of the doctors felt they didn't have enough training. They felt like they were being asked to fix a complex engine without the latest diagnostic tools.
• The Reality Check: Even though they felt unprepared, the doctors with more experience and those who had taken extra courses didn't necessarily score higher on the knowledge test. This suggests that standard medical school isn't teaching enough about supplements, and even experienced doctors are flying blind on this specific topic.

4. The Big Picture: Why Does This Matter?

Imagine you are driving your car. You see a sign for a "Super Turbo Kit" that promises to double your speed. You buy it and put it in.

• If your mechanic knows nothing about it, they might just say, "Sure, go ahead."
• But if that "Super Turbo" actually melts your engine (like a supplement causing liver damage or interacting with your heart medication), you are in trouble.

The study concludes that Italian doctors are willing to be the safety inspectors, but they need better training manuals. They recognize that patients are buying these products online from anyone, often without advice. The doctors want to step in and say, "Wait, let's check if this is safe for your specific engine," but they need more education to do it confidently.

The Takeaway

The doctors are the guardians of the road. They know they have a huge role to play in stopping patients from crashing because of bad supplement choices. But right now, they are asking for a refresher course so they can give advice that is based on facts, not just guesses.

Technical Summary

1. Problem Statement

The use of food supplements (dietary supplements) in Italy has surged, with 32 million citizens using them and a 12% sales increase since 2020. Despite their widespread availability through pharmacies, herbal stores, and e-commerce without prescriptions, significant risks exist, including mislabeling, false health claims, drug interactions, toxicity, and potential carcinogenic effects. While General Practitioners (GPs) are central to managing these risks and guiding patient behavior, there is a lack of empirical data regarding Italian GPs' specific knowledge, attitudes, and prescribing practices concerning supplements. This study aims to fill that gap to improve patient safety and evidence-based counseling.

2. Methodology

• Study Design: A cross-sectional observational study conducted between March and July 2024.
• Population: Italian General Practitioners (GPs). The target population was 35,398 active GPs (based on 2024 ISTAT data).
• Sampling: A survey was distributed via email through the Scientific Society of Italian General Practitioners (SIMG).
  • Sample Size: 7,952 invitations sent; 233 complete responses collected (Response rate: 2.9%).
  • Inclusion Criteria: Active GPs in Italy willing to participate.
  • Exclusion Criteria: Retired physicians.
• Instrument: A 62-question questionnaire adapted from a previous study on pharmacists.
  • Section A (Knowledge): 28 True/False questions covering regulations, interactions, specific nutrients (Vitamins D, B12, etc.), and risks. A score >60% was defined as "adequate knowledge."
  • Section B (Attitudes & Practices): 34 questions on a 5-point Likert scale (1=Strongly Disagree, 5=Strongly Agree) covering five latent variables: need for education, perception of the GP's role, external influences, counseling behavior, and specific prescribing habits.
  • Demographics: 9 questions on age, gender, experience, training, and work setting.
• Statistical Analysis:
  • Descriptive statistics (frequencies, means).
  • Reliability testing using Cronbach's Alpha and McDonald's Omega.
  • Group comparisons using Mann-Whitney U and Kruskal-Wallis tests for continuous/ordinal variables.
  • Chi-square tests for independence between knowledge adequacy and socio-demographic groups.
  • Significance level set at $p < 0.05$.

3. Key Contributions

• First National Study: This is the first study specifically targeting Italian GPs regarding dietary supplement knowledge and practices.
• Comparative Insight: It provides a baseline for comparing GP knowledge against previous findings in pharmacists (from the same research group) and international studies.
• Identification of Knowledge Gaps: It highlights specific areas where GPs lack confidence or accuracy, particularly regarding the distinction between supplements and drugs, and specific nutrient interactions.
• Attitude-Practice Correlation: It links the perceived role of the GP in patient education with actual counseling behaviors, revealing a strong desire for further training despite self-reported adequate knowledge.

4. Key Results

• Demographics:
  • 54.9% Female, 44.6% Male.
  • 68.2% worked in urban settings; 53.6% worked in group practices.
  • 61.8% had specific training in family medicine, but only 17.6% had specific training on dietary supplements.
• Knowledge Scores:
  • Overall Adequacy: 69.1% of GPs achieved an "adequate" knowledge score (>60% correct). The mean score was 18.9/28.
  • Specific Weaknesses:
    • Only 17.6% correctly identified that supplements can contain non-labeled toxic ingredients.
    • Poor knowledge on Calcium/Vitamin D efficacy for fractures (28.8% correct) and Omega-3 efficacy (33.1% correct).
    • Confusion between supplements and pharmacological products was common.
  • Strengths: High knowledge on drug interactions (85.4%) and the link between high-dose protein and kidney damage (97.4%).
  • Subgroup Analysis: No significant differences in knowledge scores were found based on gender, experience, or specific training, except for work setting: GPs in rural areas scored significantly higher (79.7%) than those in urban areas (64.2%).
• Attitudes and Practices:
  • Role Perception: 98.7% agreed they play an important role in prescribing; 98.3% are involved in lifestyle counseling.
  • Training Needs: Despite high role perception, only 66.5% felt they had adequate training.
  • Counseling Behavior: Most GPs actively advise patients (mean score 4.3–4.7 on Likert scale) and prioritize evidence-based prescribing.
  • Experience Factor: GPs with >10 years of experience were more confident in identifying misuse and side effects.
  • Reliability: The attitude/practice sections showed good reliability ($\alpha > 0.7$), while the knowledge section had low reliability ($\alpha = 0.5$), suggesting item heterogeneity.

5. Significance and Conclusion

• Clinical Implication: While Italian GPs generally possess adequate knowledge and recognize their pivotal role in managing supplement use, significant gaps remain in specific areas (e.g., toxicity, specific nutrient efficacy). This creates a risk for patient safety given the high volume of unsupervised supplement use.
• Educational Need: There is a strong consensus among GPs for more specific, evidence-based education on supplements. The study suggests that current training is insufficient despite the GPs' willingness to counsel.
• Policy Impact: The findings support the need for targeted continuing medical education (CME) programs focusing on supplement-drug interactions, regulatory nuances, and specific nutrient risks to mitigate misuse and adverse events.
• Limitations: The study is limited by a low response rate (2.9%) and the low internal reliability of the knowledge section. However, it remains a critical baseline for future interventions in the Italian healthcare system.

Conclusion: Italian GPs are proactive in counseling regarding dietary supplements but require enhanced, specific training to bridge the gap between their perceived role and their technical knowledge, particularly regarding safety risks and efficacy claims.