Significant change in the profile of recruitable patients

To assess the impact of a muscle-targeted nutritional therapy consisting of nutritional counseling and high-quality whey protein-based oral nutritional supplements enriched with leucine and vitamin D, on the recovery of post-COVID-19 patients

Inclusion Criteria:

• Sarcopenia (revised European Working Group on Sarcopenia in Older People criteria)
• Recent discharge from hospital for COVID-19
• Informed consent

Exclusion Criteria:

• Any malignant disease during the last five years
• Known kidney failure (previous glomerular filtration rate <30 ml/min);
• Known liver failure (Child B or C)
• Psychiatric disease
• Endocrine disorders associated with disorders of calcium metabolism (excluding osteoporosis)
• Indications related to the study product:

More than 10 µg (400 IU) of daily Vitamin D intake from medical sources. More than 500 mg of daily calcium intake from medical sources. Adherence to a high energy or high protein diet up or use of protein containing or amino acid containing nutritional supplements up to three months before starting the study.

• Known allergy to milk, milk products or other components of the proposed interventions
• Indication to or ongoing artificial nutrition support
• Inclusion in other nutrition intervention trials
• Investigator's uncertainty about the willingness or ability of the subject to comply with the protocol requirements
• Refusal