Analysis of selenium content in commercial dietetic products

Selenium (Se) is largely associated with the protein component of foods. The processing of elemental feeds and artificial formulations used in clinical dietetic practice can, therefore, result in significant losses of Se from these products and the Se status of patients consuming these feeds may be compromised. A selection of commercial formulas typically used for enteral feeding, and for patients with cystic fibrosis, phenylketonuria and maple syrup urine disease were analysed for Se micro-fluorimetrically. Low Se contents were found in all food supplements except for Peptisorbon (0.09 mg Se/2000 kcal) and Clinifeed Protein Rich (0.08 mg Se/2000 kcal) which contained adequate daily Se levels according to the American RDI. The results show that a number of feeds are low in Se, especially those used for patients with cystic fibrosis and maple syrup urine disease. An investigation of the Se status of patients on these formulations may indicate the need for Se supplementation.