Knowledge and attitudes as correlates of dietary supplement use among adults in Saudi Arabia: a cross-sectional online survey of a predominantly Riyadh-based convenience sample.
Alruwaili N, Alsenaidy A, et al. • Frontiers in public health • 2026
In this cross-sectional convenience sample of adults in Saudi Arabia, dietary supplement use was common and attitudinally endorsed, yet self-rated dosing competence was limited and online sources dominated information-seeking, with knowledge and attitudes independently associated with use though directionality cannot be established.
Key Findings
Results
Dietary supplement use was reported by 40.1% of the 725 respondents.
291 of 725 respondents were classified as current users (40.1%).
Current DS use was defined as agreement ('agree' or 'strongly agree') with the item 'Do you currently use dietary supplements?'
The sample was predominantly young, male, and Riyadh-based, recruited via non-probability convenience sampling.
The survey was conducted between 14 March and 14 June 2026 using a structured, self-administered Arabic questionnaire.
Results
Nearly all respondents had heard of dietary supplements, but only a minority reported knowing the correct doses.
97.4% of respondents had heard of dietary supplements.
Only 32.0% agreed that they knew the correct doses.
This gap suggests high awareness does not translate to informed or competent use.
Results
The internet was the predominant source of information about dietary supplements, while pharmacists were rarely cited.
The internet was the leading information source, named by 57.0% of respondents.
Pharmacists were named as an information source by only 3.9% of respondents.
Despite internet dominance, 56.4% of current users reported having consulted a health professional before starting supplement use.
Results
Attitudes toward dietary supplements were predominantly favorable across the sample.
82.9% of respondents agreed that dietary supplements are safe when used correctly.
Favorable attitudes were associated with higher odds of being a current user in the multivariable model.
Results
Among current users, daily use and vitamins were the most common patterns of supplement consumption.
69.4% of current users reported daily use of dietary supplements.
Vitamins were the most commonly used supplement type, reported by 83.5% of users.
Results
Following a special diet was independently associated with higher odds of dietary supplement use.
In the multivariable binary logistic regression model (n = 666; 270 users), following a special diet was associated with an adjusted odds ratio of 2.44 (95% CI 1.55–3.85) for current supplement use.
This was among the strongest positive predictors of use in the adjusted model.
Results
Lower self-rated knowledge was independently associated with significantly reduced odds of dietary supplement use.
Relative to the reference category of excellent self-rated knowledge, moderate self-rated knowledge was associated with aOR 0.34 (95% CI 0.22–0.53).
Poor self-rated knowledge was associated with aOR 0.11 (95% CI 0.06–0.20).
Equivalently, current users rated their own knowledge more highly than non-users.
The cross-sectional design means the direction of this association cannot be established — it is unclear whether higher knowledge leads to use or whether use leads to higher self-rated knowledge.
Results
Neutral and negative attitudes toward dietary supplements were independently associated with substantially lower odds of current use.
Relative to the reference category of positive attitude, a neutral attitude was associated with aOR 0.40 (95% CI 0.27–0.59).
A negative attitude was associated with aOR 0.07 (95% CI 0.03–0.20).
These associations are consistent with attitude influencing behavior, but the cross-sectional design precludes causal inference.
Methods
The multivariable model had a reduced analytic sample compared to the full survey sample due to missing data.
The full survey sample comprised 725 respondents.
The multivariable logistic regression was conducted on n = 666, with 270 classified as users.
This represents a reduction of 59 respondents from the full sample, presumably due to missing covariate data.
What This Means
This research suggests that dietary supplement use is common among adults in Saudi Arabia, with about 4 in 10 survey respondents reporting current use. Vitamins were the most popular type, and most users took them daily. While nearly everyone had heard of dietary supplements and the majority viewed them as safe when used correctly, a major gap was found in practical knowledge: only about 1 in 3 respondents felt confident they knew the correct doses. The internet was by far the most common place people turned for information, while pharmacists — who might offer more personalized guidance — were consulted by very few.
The study found that people who followed a special diet were more than twice as likely to use supplements compared to those who did not. People who rated their own supplement knowledge as excellent and who held positive attitudes about supplements were also far more likely to be users. Interestingly, more than half of current users did report consulting a health professional before starting, which suggests professional guidance is not entirely absent but may not be universal.
This research matters because it highlights a disconnect between the widespread use of dietary supplements and the limited confidence people have in knowing how to use them safely and correctly. The heavy reliance on internet sources for supplement information, rather than trained healthcare providers like pharmacists or doctors, raises questions about the quality and accuracy of the information guiding people's choices. Because the study was conducted online and relied on a convenience sample that was mostly young, male, and from Riyadh, these findings may not represent all adults in Saudi Arabia, and the study design cannot tell us whether better knowledge and attitudes lead to supplement use or whether using supplements leads people to feel more knowledgeable.
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Alruwaili N, Alsenaidy A, Suhluli M, Alahmari H, Alafif N, Zarah A, et al.. (2026). Knowledge and attitudes as correlates of dietary supplement use among adults in Saudi Arabia: a cross-sectional online survey of a predominantly Riyadh-based convenience sample.. Frontiers in public health. https://doi.org/10.3389/fpubh.2026.1929339