Table 1

Supplementation for children on the ketogenic diet (adapted from Kossoff et al 5)

Universally recommended
 Multivitamin with minerals (including trace minerals)
  • Thiamine, folate, pantothenic acid, calcium, phosphorus, iron, vitamin D and trace mineral intake likely to be insufficient.13

  • Omega-3 may be low if dietary fat content primarily from animal sources, eg, butter, cream.13

 Calcium with vitamin D
  • For bone health. Vitamin D levels often low in children starting ketogenic diets.14 Many anticonvulsants associated with decreased bone mineral density.15

Extra supplementation (suggested by some group members):
 Oral citrates
  • Uric acid stones more common than calcium oxalate stones. Citrates reduce risk of stone formation11 but kidney stones may still occur in 1% of those on citrates.10

  • Gastrointestinal problems in ≤75% patients, constipation most commonly seen.11

 Additional selenium, magnesium, zinc, phosphorus, vitamin D
  • Sudden death, prolonged QT intervals and dilated cardiomyopathy reported with selenium deficiency, but most supplements contain adequate selenium.10

  • Phosphorus not included in most multivitamin supplements, but might improve bone mineralisation and is an acid buffer.13

  • Carnitine deficiency rare, but more common in patients taking valproate.10

  • Anecdotally, energy levels/seizure control improved with carnitine supplementation.13

  • Carnitine deficiency associated with serious cardiac and hepatic disease; consider when unexplained fatigue or muscle weakness.10

  • Carnitine needed for long-chain triglyceride breakdown so not necessary for children on MCT diets.10

  • IKDSG states carnitine supplementation controversial and does not recommend empiric use.5

 MCT oil or coconut oil (source of MCT)
  • For constipation (small amounts).5

 Sodium and potassium
  • To add to modular formulas.

  • IKDSG, International Ketogenic Diet Study Group; MCT, medium-chain triglyceride.