The increasing adoption of diverse dietary regimens, whether for health, ethical, or personal reasons, has drawn global attention to their potential impact on nutritional status (1,2). In Saudi Arabia, rapid urbanization and the influence of Western dietary habits have contributed to major shifts in eating patterns, including higher consumption of processed and fast foods alongside a growing interest in health-conscious diets (3). A recent study identified the most commonly followed dietary regimens in Saudi Arabia as the ketogenic diet, intermittent fasting, gluten-free diet, and calorie restriction, with vegetarianism also gaining popularity (4,5).While these diets may offer certain benefits, they also present nutritional challenges. The ketogenic diet, though sometimes effective for medical conditions, has shown inconsistent longterm weight loss outcomes and is often difficult to sustain due to its restrictive nature (6). Intermittent fasting and calorie restriction may require careful planning to ensure adequate nutrient intake (7,8). Similarly, vegetarian and vegan diets, if not properly managed, can lead to deficiencies in key vitamins such as B12 and D (9).Micronutrients are essential vitamins and minerals required in small quantities, yet they are fundamental to overall health and wellbeing (10). They are available in various forms, including tablets, capsules, and liquids, and may consist of a combination of vitamins, minerals, herbs, and other compounds (11). These nutrients support various physiological functions, including metabolism, immune response, and bone health (12). They are also directly associated with mental performance, emotional stability, and energy levels (11). In Saudi Arabia, the use of dietary supplements is widespread. A study conducted in Riyadh found that 63.2% of participants reported current or past use of nutritional supplements (13), with 53.6% of users being female and 42.5% male (14).There is a well-established relationship between dietary regimen and vitamin intake, as different diets can influence both the quantity and type of vitamins consumed. For example, studies in Hong Kong and India have reported that up to 80% of vegans are deficient in vitamin B12 and iron, nutrients found naturally only in animal-based foods (15)(16)(17). Similarly, ketogenic diets may be associated with deficiencies in vitamin D, magnesium, calcium, iron, phosphorus, and potassium, due in part to reduced sun exposure and altered fat metabolism (18,19). Despite growing global attention to the nutritional consequences of various dietary regimens, few studies have examined their micronutrient implications in the Saudi context. This lack of localized data on how specific dietary regimens influence micronutrient intake creates a gap in public health knowledge, particularly in populations experiencing rapid dietary transitions. In line with these gaps, the present study aimed to assess the prevalence of commonly practiced dietary regimens among adults in Riyadh, determine the extent of micronutrient supplementation within this population, and examine the association between dietary patterns and micronutrient intake. Accordingly, the study aimed to address the overarching research question: To what extent do the type and duration of dietary regimens influence micronutrient supplementation among adults in Riyadh?A cross-sectional study was conducted among Saudi adults aged 18-45 years residing in Riyadh, Saudi Arabia, between December 2024 and March 2025. Participants were recruited using non-probability convenience sampling through online platforms (WhatsApp, X, and Telegram). Adults older than 45 years were excluded to minimize age-related variability in nutrient absorption and dietary behavior. Of the 412 questionnaires received, 400 valid responses were included in the final analysis. Participants who were pregnant or breastfeeding were excluded to avoid confounding due to altered nutritional requirements.Data were collected using an online questionnaire that assessed sociodemographic characteristics, dietary regimen practices, and micronutrient supplementation. The instrument underwent content validation by five academic experts, and its internal consistency was confirmed (Cronbach's α = 0.80). Although no pilot study was conducted, expert feedback was used to revise the questionnaire for clarity and comprehensiveness.Recruitment targeted adults in the general population who engaged with digital health content and dietary practicesreflected in the predominance of young, highly educated female respondents. Participation was voluntary, and informed consent was obtained electronically prior to enrollment.Data were analyzed using JMP Pro Version 18 and Microsoft Excel (20,21). Descriptive statistics were computed to summarize participant characteristics. Associations between categorical variables were assessed using the chi-squared and Fisher's exact tests, with statistical significance set at a p-value of < 0.05 (two-tailed). Missing data were excluded listwise without imputation.A logistic regression analysis was conducted to examine the association between micronutrient supplementation and diet adherence duration. For this analysis, three dietary categories-vegan, Mediterranean, and gluten-free-were merged into a single "Other Diets" group due to small cell counts that resulted in unstable model estimates. This grouping improved statistical stability and allowed for more reliable odds ratio estimation.Ethical approval was obtained from the Institutional Review Board of Princess Nourah Bint Abdulrahman University (Approval No. 24-0931). Participation was anonymous, and data confidentiality was maintained throughout the study.Frontiers in Nutrition 03 frontiersin.orgTable 1 presents sociodemographic and nutrition-related characteristics. The majority of participants were aged 18-24 years (58%) and female (71.5%). A similar proportion (71.5%) held a bachelor's degree or higher. Approximately half of the participants were overweight or obese (44%), while 43.25% had a normal weight. Approximately one-third (37%) reported following a diet within the previous 6 months. Supplement use was reported by 45.11% of participants. Among supplement users, 63% obtained supplements via prescription, with female participants being significantly more likely than male participants to do so (χ 2 (1, N = 130) = 19.9, p < 0.0001).Figure 1 shows an overview of micronutrient consumption. Among vitamins, vitamin D was most commonly used (31%), followed by multivitamins (20%) and vitamin B12 (16%). For minerals, iron was the most frequently consumed (33%), followed by zinc (19%) and magnesium (16%).Table 2 summarizes the association between micronutrient supplement consumption and dietary regimen. Supplement use was most common among individuals following gluten-free (75%) and keto (66.67%) diets. Although supplement users were more likely to follow gluten-free (p = 0.0445) and low-carbohydrate (p = 0.0456) diets, there was no significant association between supplement consumption and overall dietary regimens.Figure 2 shows that vitamin D was the most commonly consumed supplement across all dietary patterns, with the highest use among individuals following gluten-free (30.61%), low-fat (29.81%), and calorie-restricted diets (29.79%). Several diets demonstrated significant associations with specific vitamins: keto and low-carb diets were associated with multiple vitamins (A, D, K, and B12), and a lowcarb diet was also associated with vitamin C and multivitamins. The DASH, vegan, Mediterranean, gluten-free, and low-fat diets also showed selective associations, particularly with vitamins E, K, and folate. In contrast, intermittent fasting and calorie-restricted diets showed similar intake trends but no significant vitamin-diet associations. Overall, vitamin D was the most commonly used supplement across diet types, with certain diets showing unique associations with certain vitamins.Figure 3 illustrates mineral consumption across diet types, showing that iron is the most frequently consumed mineral in all groups, with the highest intake among individuals following gluten-free (41.7%), low-fat (38.1%), and Mediterranean (36.6%) diets. Zinc and magnesium were the next most common minerals, particularly among those following keto, intermittent fasting, or calorie-restricted diets. Several diets showed notable mineral-diet associations, including keto (calcium, p = 0.0186; selenium, p = 0.0166), low-carb (calcium, p = 0.0416), DASH (potassium, p = 0.0085), vegan (calcium, p = 0.0090; potassium, p = 0.0240), Mediterranean (potassium, p = 0.0434), gluten-free (calcium, p = 0.0375; potassium, p = 0.0166), and low-fat (calcium, p = 0.0042; potassium, p = 0.0421). Overall, iron dominates mineral supplementation, while calcium and potassium demonstrate significant associations with multiple dietary patterns.Table 3 presents the distribution of popular diet types by sex and BMI. The calorie-restricted diet was the most widely adopted (71.62%) and maintained for the longest duration (29.05% for 4-6 months). Intermittent fasting was most popular among female participants (56.08%), while only 10.14% of male participants followed it, indicating a significant sex difference (p = 0.0011). Male participants most commonly chose the calorie-restricted diet (18.24%). Calorie restriction was also the most commonly followed diet among both normalweight (31.08%) and overweight/obese participants (37.84%), with a significant association with BMI (p = 0.0441). Among underweight participants, calorie restriction, intermittent fasting, and low-carb diets were followed equally (2.70%). The low-carb diet showed significant associations with age (p = 0.0484; more common among 18-24-year-olds) and sex (p = 0.0344; more common among female participants). The gluten-free diet was significantly more commonly followed by individuals aged 36-45 (p = 0.0191).Table 4 presents the association between micronutrient consumption and the duration of adherence to different dietary regimens. No significant associations were observed for the majority of diets; however, participants practicing intermittent fasting for 4-6 months had significantly higher odds of consuming supplements (OR = 3.96, p = 0.012). Similarly, individuals adhering to the combined 'Other Diets' group for 4-6 months showed markedly increased supplement use (OR = 7.70, p = 0.008).In Saudi Arabia, the growing popularity of various dietary trends among young adults highlights the need to understand their nutritional effects. This study examines the link between dietary regimens and micronutrient supplementation, as different diets can influence both the amount and type of vitamins consumed, highlighting the relevance of this research. Our findings reported that approximately one-third of participants had followed at least one structured diet in the previous 6 months. The most commonly adopted diet was calorie restriction, a pattern consistent with its reputation for simplicity and flexibility. Unlike diets that eliminate entire food groups, calorie restriction can be practiced without significant lifestyle disruption, likely contributing to its popularity. This contrasted with previous findings, which reported much lower engagement with calorie-restricted diets in a Saudi sample (22). Approximately half of the participants reported practicing intermittent fasting, which mirrors previous findings in Riyadh, where a high prevalence of intermittent fasting was also observed (23). Its appeal may stem from cultural familiarity with fasting and its perceived effectiveness.Interestingly, our study found that women were significantly more likely than men to adopt intermittent fasting. This pattern aligns with findings that identified gender as a key factor influencing adoption (24). This could reflect the greater social and psychological pressure on women to conform to certain body ideals and gendered differences in health behaviors. Low-carbohydrate diets were frequently reported by participants in this study, with adoption levels noticeably higher than those documented in earlier Saudi research (4) and European contexts such as Sweden (25). This rise in popularity may reflect increased public interest in reducing carbohydrate intake as a strategy for weight control and improved metabolic health. The influence of social media, fitness trends, and widespread discussions around the effects of carbs may have contributed to the growing appeal of this diet, particularly among younger and working-age individuals, who comprised the majority of our sample. A moderate portion of the participants adopted low-fat, Mediterranean, and DASH diets. Compared to older findings, adoption of low-fat diets appears to be more common in our sample than in some previous studies but lower than among specific populations such as medical students (4, Overview of micronutrient consumption. Diet type and vitamin consumption. Diet type and mineral consumption.10.3389/fnut.2026.1686609Frontiers in Nutrition 06 frontiersin.org 26). These variations may be due to differences in nutritional literacy or access to professional dietary guidance. A good portion of participants in our study followed the Mediterranean diet, showing higher adherence compared to earlier Saudi research (27), which reported a much lower rate. This may reflect growing awareness of the diet's health benefits and increased exposure through the media and healthcare professionals.In contrast, although several participants reported following the DASH diet, findings from the UAE suggest that overall adherence and awareness of this diet remain low in the region (28). This may indicate that, unlike the Mediterranean diet, the DASH approach has not yet gained significant traction among the public. Vegan diets were reported by approximately one-third of participants, substantially higher than those documented in previous Saudi studies (22). This shift may reflect growing interest in plant-based lifestyles, possibly influenced by ethical considerations, health claims, or social trends. A quarter of participants also practiced gluten-free diets, much lower than earlier reports of short-term experimentation (4). The discrepancy may reflect differences in how the diet is defined or practiced, whether adopted for medical necessity, weight management, or perceived health benefits. The popularity of specific dietary regimens in Saudi Arabia is evident in the studied population. Intermittent fasting is widely practiced among Saudis, both during and outside of Ramadan (24). In comparison, a minority of participants followed ketogenic and gluten-free diets, with adherence generally short-term (4). These findings may reflect differences in familiarity, accessibility, and adherence to each dietary regimen within this population.Approximately half of the participants reported using supplements, supporting existing evidence that supplement consumption is widespread in Saudi Arabia. These findings are comparable to previous national studies that have documented similarly high usage rates, reinforcing the growing reliance on supplementation as part of modern health practices (11,29). Among specific vitamins, vitamin D emerged as the most commonly used, followed by multivitamins and Vitamin B12. This pattern mirrors findings from earlier studies in Saudi Arabia and neighboring Jordan (30,31). Vitamin D deficiency remains a common issue due to limited sun exposure and lifestyle habits that reduce natural vitamin synthesis. Females were significantly more likely than males to use micronutrient supplements, mostly by prescription. Alfawaz et al. similarly found higher supplement use among Saudi female adolescents (33% vs. 17.9%) (32). Both results confirm that sex strongly influences supplement consumption in Saudi populations.The widespread use of vitamin D reflects public awareness of this deficiency and may increase screening and prescribing efforts by healthcare professionals. The majority of participants reported using prescribed supplements when examining supplementation sources, while a smaller portion relied on over-the-counter or self-prescribed options. This trend is consistent with local studies that noted healthcare providers' strong role in supplement distribution, especially pharmacists (29). However, it contrasts with findings from Jordan, where self-prescription was more common (31), indicating that cultural and healthcare system differences may shape supplement access and trust in professional guidance. Beyond general consumption patterns, this study also assessed the association between dietary regimens and supplement use. The majority of individuals following gluten-free and low-carb diets reported using supplements, which aligns with international research emphasizing the risk of micronutrient deficiencies on restrictive diets. Gluten-free diets have been associated with inadequate intake of iron, folate, vitamin D, and B12, while low-carb regimens may reduce essential nutrients such as thiamine, calcium, and magnesium (33,34). Supplement use among these groups may reflect a preventive strategy and a response to emerging deficiency symptoms. Across nearly all dietary groups, vitamin D remained the most commonly used supplement, a trend consistent with international literature on restricted diets such as low-calorie (35), vegan (36), and gluten-free plans (37). Participants following ketogenic and low-carb diets also showed frequent use of vitamin D, multivitamins, and B12, further supporting evidence that these diets, although popular, may create nutritional gaps that require careful management (17).Moreover, our findings on the significant associations between specific dietary regimens and mineral intake are in line with existing international literature. Among individuals following vegetarian or vegan diets, iron intake emerged as a major concern. A meta-analysis of 24 cross-sectional studies confirmed that adult vegetarians tend to have significantly lower serum ferritin levels compared to non-vegetarians (17). Similarly, vegans have been found to consistently consume less calcium than both vegetarians and omnivores (p < 0.0001), highlighting the importance of ongoing calcium monitoring within this population (38). Participants following low-carbohydrate or ketogenic diets have also demonstrated patterns of potential micronutrient insufficiency. Evidence from clinical trials and systematic reviews has shown that these diets are commonly associated with reduced intake or levels of calcium, magnesium, iron, and thiamine, with some studies even reporting declines in serum calcium over time (19,39).The lower calcium status observed in ketogenic dieters may result from limited consumption of dairy and legumes, as well as potential changes in bone metabolism due to chronic metabolic acidosis, which can increase urinary calcium loss (40). While initial serum values may remain within normal ranges, prolonged adherence to such diets without adequate planning poses risks that may necessitate supplementation.Gluten-free diets, although essential for individuals with celiac disease, may also negatively affect mineral absorption and bone health. A long-term study revealed that despite higher calcium intake, individuals on gluten-free diets had lower fractional calcium absorption and significantly reduced bone mineral density (BMD) compared to controls (p < 0.001 and p < 0.05, respectively) (41). These findings suggest that increased intake alone may not fully compensate for impaired calcium absorption, emphasizing the need for ongoing bone health monitoring in this group.Additionally, low-fat diets-which are often perceived as healthy and balanced-may indirectly impair calcium metabolism. This occurs through reduced absorption of fat-soluble vitamin D, a nutrient critical for calcium uptake. Clinical research shows that consuming vitamin D with low-fat meals leads to significantly lower serum 25(OH)D levels, potentially decreasing calcium absorption efficiency (42). This underscores the frequently overlooked risk of micronutrient disruption, even in well-regarded dietary patterns. Taken together, these findings underscore a broader understanding: restrictive dietary patterns-whether motivated by medical needs, ethical beliefs, or weight management goals-can inherently increase the risk of mineral imbalances. The supplementation behaviors observed among participants in this study likely reflect both professional dietary guidance and individual efforts to manage or prevent such deficiencies.This study offers an important contribution as one of the first investigations in Riyadh to examine micronutrient supplement use in the context of popular dietary regimens, supported by an adequate sample size and coverage of multiple diet types. 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