Stage 4 or 5 CKD (eGFR with CKD-EPI 2009 creatinine equation \< 30 mL/min/m2), whitout renal replacement therapy or kidney transplantation
Protein intake 0.6-0.8 g/kg/d (estimated with Moroni formula)
Social security cover
Written informed consent
You may not be if
Hospitalization in the past 3 months
Corticosteroids (\> 7.5 mg/d), cytotoxic or immunosuppressive drugs
Severe symptomatic heart (NYHA 3 or 4) or liver failure (Child Pugh B or C)
Respiratory failure requiring oxygenotherapy
Ongoing infection, autoimmune disease or cancer
Pregnant (e.g., positive human chorionic gonadotrophin \[HCG\] test) or lactating patients
Risk of pregnancy: any woman who does not fulfil one of the following criteria:
* post-menopausal (aged \> 45 years with amenorrhea for more than 2 years, or of any age with amenorrhea for more than 6 months and an FSH level \> 40 mUI / mL)
* permanent sterilisation (e.g., occlusion/bilateral ligature of the fallopian tubes, hysterectomy, bilateral salpingectomy, bilateral ovariectomy) or constitutional sterility
* of childbearing age and using an efficient method of contraception, begun at least 28 days before inclusion. Efficient contraception methods are: oral, injectable or implantable hormonal methods intra-uterine devices sterilisation of the male partner if he is the sole partner abstinence, if compatible with the preferred and usual lifestyle of the individual NB: if child bearing potential changes during the study, the woman must start taking one of the efficient methods of contraception as described above.
Patients with psychiatric or cognitive disorders rendering them unable to give written informed consent
Patients unwilling to participate in the study
Hypersensitivity to the active substances in Ketosteril®
Hypercalcaemia
Hypophosphatemia
Patient under a legal protection (curatorship or tutorship)
