High serum phosphate has been observed to induce cellular senescence, vascular dysfunction and artery calcification. Even modestly elevated serum phosphate concentrations, within the normal range, have consistently been linked to atherosclerosis, increased risk of CVD and CVD mortality. Inorganic phosphate is incorporated as an additive in practically all ultra-processed food (UPF), whose consumption has increased substantially over the last decades worldwide. Unlike organic phosphate naturally present in fresh and unprocessed foods, the inorganic phosphate from additives has a high bioavailability and is almost entirely absorbed in the digestive tract. An accurate quantification of dietary phosphate intake is currently not possible due to a lack of a correct, comprehensive, and quantitative labeling system of additives on packaged food. UPF is the main source of the so-called “hidden phosphate” that cannot be properly quantified in population dietary survey studies. Attempts to estimate the intake of dietary phosphate in the Nordic countries indicate a range from 1000 to 1900 mg/day, two- to three-times higher than the recommended intake in the Nordic Nutrition Recommendations 2023. The food composition databases used for estimating these numbers generally do not contain correct information on added inorganic phosphate, hence the numbers might be even higher. The phosphate homeostasis in the body is regulated through a complex interaction between gastrointestinal absorption, bone remodeling, and urinary excretion. Dietary phosphate intake promotes the production of hormones, e.g., fibroblast growth factor 23 (FGF-23) and parathyroid hormone (PTH), which increases the renal clearance of phosphate, reverting a high post-prandial blood phosphate concentration to fasting state. Thus, in normal conditions, phosphate excretion via urine could be used as a biomarker of P absorbed in the digestive tract. The aim of the project is therefore to assess the association between urinary phosphorus and major adverse cardiovascular events (MACE) in men and women from the national infrastructure SIMPLER, including repeated measurements in a subset of women.