[www.ncbi.nlm.nih.gov]

Carnitine deficiency is a condition characterized by low carnitine levels in the body.

Carnitine (beta-hydroxy-gamma-trimethylammonium butyrate) is an indispensable water-soluble molecule derived from amino acids.[1][2] In non-vegetarians, dietary intake is the primary source of carnitine and accounts for almost three-fourths of the total body stores.[3] The main dietary source of carnitine is red meat, poultry, and dairy products.[4] The bioavailability of dietary carnitine is between 54% to 87%.[5] The remaining one-fourth of the carnitine pool can be produced endogenously from lysine and methionine mostly by the liver and kidneys.[3][6] Vegetarians have a relatively lower plasma carnitine level than non-vegetarians.[7] In strict vegetarians, most of the carnitine (>90%) is produced endogenously.[3] Despite variabilities in dietary carnitine intake, the plasma carnitine level is maintained within the normal range by an efficient renal reabsorption system while excessive carnitine is promptly excreted in the urine.[8] About 90% to 99% of the filtered carnitine is usually reabsorbed by the renal tubules.[3]

Carnitine plays a substantial physiological role in lipid metabolism and intermediary metabolic pathways.[5] Through the carnitine shuttle, carnitine helps in transporting the long-chain fatty acids from the cytoplasm to the mitochondrial matrix for subsequent degradation for beta-oxidation, which is detailed in the pathophysiology section (figure).[3]

Under normal physiological conditions, fatty acids are the main source of energy during fasting.[6] Energy production from fatty acids occurs via beta-oxidation of fatty acids in the liver, heart, and skeletal muscles.[6] Beta oxidation of the long-chain fatty acid (LCFAs) occurs exclusively in the mitochondrial matrix.

In carnitine deficient states, LCFAs cannot be effectively transported to the mitochondria matrix for oxidation and subsequent utilization in Kreb’s cycle and ketone body production. During periods of fasting, improper utilization of fatty acids impairs gluconeogenesis and characteristically leads to nonketotic or hypoketotic (no or minimal ketone body production respectively) hypoglycemia.[3] When fatty acid oxidation is impaired, glucose is readily consumed without replenishment from gluconeogenesis.[6]

Accumulation of fat in the liver causes steatosis and impairment of ketone body production.[5][6][8] In the heart and skeletal muscles, this abnormal accumulation results in cardiomyopathy and myopathy respectively.[5][6] Heart derives two-thirds of its energy from free fatty acids and this predisposes patients with impaired carnitine metabolism to the development of cardiomyopathy.[6] Additionally, impaired lipid metabolism can affect the electrical rhythm of the heart resulting in arrhythmias.[6] The brain utilizes ketone bodies as an alternate energy source in fasting states. These ketones are derived from acetyl-CoA from fatty acid oxidation and in carnitine deficiency, this is defective.[6] Unstable energy and metabolic abnormalities can impair brain function with loss of consciousness and metabolic encephalopathy.[6][17]


The mainstay of primary carnitine deficiency involves lifelong treatment with a high dose of oral L-carnitine (100 to 200 mg/kg daily dose in 3 divided doses).[3][4] The oral bioavailability of L-carnitine is 5% to 18%.[5] L-carnitine is a fairly safe medication, and few side effects associated with high doses include diarrhea and intestinal discomfort. Additionally, bacterial degradation of unabsorbed oral L-carnitine in the bowel results in trimethylamine, which has a peculiar fishy odor.[3][6]

Continued L-carnitine administration prevents hypoglycemic episodes as well as cause improvement in myopathic symptoms.

It is crucial to avoid episodes of hypoglycemia in PCD by frequent feeding and avoiding fast states.[17]

Secondary carnitine deficiency (SCD) could result from multiple causes, either from a decrease in carnitine intake or more commonly from an increase in renal excretion. SCD may result from severe malnutrition, ketogenic diet, severe malabsorptive states, extremely preterm infants, and prolonged parenteral nutrition without adequate L-carnitine supplementation.[4][6]

the most common manifestations include hypoketotic hypoglycemia, myopathies of both skeletal and cardiac muscles.[3][15][21][22] Most often, the manifestations are precipitated or worsened by either fasting or intercurrent illnesses.[15]

In patients with SCD, it is crucial to prevent hypoglycemic episodes by frequent feeding and avoid fasting during day time and continuous corn starch supply during the night.[3][17][3] Patients should consume high carbohydrates and low-fat diets that provide energy in the form of medium-chain triglycerides, which can enter into the mitochondria in the absence of a carnitine shuttle.[21]

continuous corn starch supply during the night

Kindly explain.

I found this about raw corn starch by searching

[trialbulletin.com]

"As the essential management for patients with glycogen storage disease (GSD), the extended release cornstarch has been proved superior to prevent hypoglycemia since 1980s. Its application has elevated GSD patients' quality of life and prolonged their survival. In view of its charicteristic of chronic release in gastrointestinal tract, we will for the first time try to utilize the raw corn starch (RCS) on patients with suspected insulinoma and evaluate its efficacy of improving hypoglycemia in such patients."

[academic.oup.com]

Ground-Breaking Application of Raw Corn Starch-Based Diet in Patients with Insulinoma-Related Hypoglycemia

"Raw corn starch (RCS), as a source of slow release carbohydrate, has been used to counter the hypoglycemia caused by glycogen storage diseases. Further, the utilization of RCS in other conditions has rarely been studied. Insulinoma, a rare neuroendocrine tumor, tends to lead to life-threatening hypoglycemia "

"RCS-based diet prevented the ponderal growth induced by overeating in 76.9% of patients. In terms of safety, mild gastrointestinal discomfort was reported as the most common adverse reaction, but relieved when RCS doses were slightly reduced."

@Panchito. Many thanks for your info.