[Supplementation of L-carnitine to the severe motor and intellectual disabilities fed with enteral carnitine-deficient formulas for years].

Objective: We clarified the asymptomatic deficiency of serum free-carnitine in the severe motor and intellectual disabilities (SMIDs) fed with enteral carnitine-deficient formulas for years, and investigated the adequate method to supply enteral L-carnitine and maintain its normal levels.
Methods: In 45 SMIDs who has been fed with carnitine-deficient formulas and/or receiving valproate, the serum free-carnitine levels were examined. To the carnitine deficient cases we introduced L-carnitine and/or a carnitine-supplemented formula to normalize and maintain the serum free-carnitine levels.
Results: Thirty-one out of 34 cases (91.2%) fed with carnitine-deficient formulas for years had serum free-carnitine deficiency. Supplement of 15 - 30 mg/kg/day L-carnitine was effective to normalize the serum free-carnitine levels within 3 months. After successful supplementation, smaller dosage of L-carnitine (100 or 300 mg/day) was enough to maintain the normal levels. Replacement of the carnitine-deficient formulas to carnitine-supplemented ones was also useful to normalize the serum free-carnitine levels.
Conclusions: Smaller dosage of L-carnitine or a carnitine-supplemented formula is sufficient to normalize and maintain the serum free-carnitine levels in SMIDs fed with carnitine-deficient formulas for years.