Background: Up to 30-40% of the patients starting artificial nutritional support develop hypophosphatemia. In general, patients with mild and moderate hypophosphatemia do not have symptoms, but severe hypophosphatemia is the hallmark of refeeding syndrome.

Objective: To determine the incidence of hypophosphatemia in not critically ill patients receiving enteral feeding.

Methods: Prospective study. We assessed during seven days 181 not critically ill patients started on enteral artificial nutrition support during seven days.

Results: 51.9% of the patients were considered to be at risk of developing refeeding syndrome (United Kingdom National Institute for Health and Clinical Excellence criteria). The incidence of hypophosphatemia was 31.5%, but only 1.1% of the patients developed severe hypophosphatemia. Older age and lower plasma proteins were significantly associated with hypophosphatemia.

Conclusions: The incidence of severe hypophosphatemia in our study is low, so we can't offer robust conclusions about the risk of hypophosphatemia in the type of patients receiving enteral nutrition.