Dietary Supplement Use in Competitive Spanish Football Players and Differences According to Sex

<b>Objectives</b>: This study aimed to evaluate and compare the consumption of dietary supplements (DS) in semi-professional male and professional female Spanish football players. <b>Methods</b>: The study involved 129 football players (92 men and 37 women) who completed a validated, self-administered questionnaire on the use of DS in athletes. <b>Results</b>: The results indicated that 96.12% of the sample reported taking DS, with the main reason for consumption being performance enhancement. The most commonly consumed DS were creatine monohydrate (66.77%), caffeine (56.59%), whey protein (48.06%), isotonic drinks (37.21%), vitamin D (27.91%), energy bars (27.13%), magnesium (20.93%), and vitamin C (20.16%). Additionally, significant differences were found between sexes regarding vitamin D consumption (<i>p</i> < 0.05; OR = 3.27 [0.36-2.00]). According to the Australian Institute of Sport DS classification, group A was the most consumed, followed by group B. Significant sex differences were found in the consumption of sports foods (<i>p</i> = 0.034; OR = 3.25 [0.05-2.31]) and medical supplements (<i>p</i> < 0.001; OR = 3.75 [0.52-2.12]). Sex differences were also found in place of purchase, source of recommendation, as well as the situation and timing of consumption (<i>p</i> < 0.05). <b>Conclusions</b>: The use of DS among Spanish football players was prevalent at 96.12%, with creatine monohydrate, caffeine, and whey protein being the most commonly consumed. Differences in consumption patterns were noted between sexes.