The Role of Carnitine Monitoring and Supplementation in Children With Epilepsy on a Ketogenic Diet.
Level 4 - case-series / case-control
Single-center retrospective case series/observational cohort
PubMed 40697002 · doi:10.1177/08830738251356537
What was done
Researchers retrospectively reviewed 150 consecutive pediatric patients treated with the ketogenic diet at Johns Hopkins Hospital over an 8-year period. Carnitine concentrations (total and free carnitine) and supplementation patterns were analyzed alongside concurrent antiseizure medications (specifically valproate), ketogenic diet parameters, and seizure outcomes at 3 months.
What was found
Carnitine levels were measured in 105 of 150 patients (70%). In unsupplemented children, total carnitine remained stable (46.2 [SD 12] to 44.9 [SD 19] µmol/L, P = .80), whereas free carnitine significantly decreased from 35.8 (SD 12) to 20.1 (SD 11) µmol/L (P < .001). Patients on valproate had lower baseline total carnitine compared to those not on valproate (40.7 [SD 20] vs 52.0 [SD 15] µmol/L, P = .02). At 3 months, 83% of children with normal total carnitine achieved >50% seizure reduction compared to 60% with hypocarnitinemia (P = .06). Carnitine was supplemented in 36 patients (24%); 12 (33%) had documented clinical benefit, but supplementation showed no significant group-level difference in seizure control or ketosis.
Why it matters
This study provides longitudinal data showing that free carnitine decreases over time during ketogenic diet therapy and is lower at baseline with concurrent valproate use, helping inform monitoring protocols for pediatric epilepsy.
Limits
The study is limited by its retrospective, single-center design, lack of standardized carnitine testing (30% missing measurements), and non-randomized supplementation driven by clinician discretion, introducing confounding by indication.
Cited by
- context Children maintained on ketogenic diets frequently develop carnitine deficiency due to high rates of fat oxidation.