Methylguanidine-acetic acid

Creatine/Nutrient depletion:

  • CarbohydratesCarbohydrates: In humans, absorption of creatine appeared to be enhanced by concurrent carbohydrate ingestion (334; 295; 183; 335). In a randomized, controlled human trial, postexercise supplementation with carbohydrate and creatine resulted in similar strength gains as protein and carbohydrate (336). In humans, ingesting creatine with carbohydrates augmented glycogen supercompensation in exercised muscle (337).
  • GlucoseGlucose: In a controlled study, no changes were observed in those taking HMB plus creatine for six weeks (313). Decreased blood glucose and serum insulin levels in creatine-supplemented animals have been reported (42). In humans, neither acute nor short-term creatine supplementation influenced glucose tolerance or levels (197; 314; 193). High concentrations of insulin may enhance muscle creatine accumulation (315). This is a result of an insulin-induced transport of creatine from circulation to skeletal muscle (315) vs. creatine delivery (316). In humans, neither acute nor short-term creatine supplementation influenced measures of insulin sensitivity (314), and fasting and postprandial glucose concentrations decreased (44). In a human controlled trial, patients taking 0.3g/kg of creatine daily for five days followed by 6mg/kg of caffeine had a significant increase in glucose (354).
  • MagnesiumMagnesium: In a randomized controlled study, magnesium and creatine have been used together to increase muscle strength and power (330). In resistance-trained subjects consuming a high-protein diet, electrolytes were unchanged following 12 weeks of creatine supplementation (1).
  • PotassiumPotassium: In humans, creatine supplementation, in the heat, resulted in no significant alterations in potassium excretion rates obtained from 24-hour and exercise urine collection periods (111). In resistance-trained subjects consuming a high-protein diet, electrolytes were unchanged following 12 weeks of creatine supplementation (1).
  • ProteinProtein: In pig animal studies, high dietary protein (16% crude protein) was added to creatine monohydrate supplementation combined with a high-glycemic carbohydrate to improve lean tissue deposition (338). After 28 days, the pigs supplemented with the combination diet gained the least 10th rib fat and expressed the highest percentage fat-free carcass lean. In resistance-trained subjects consuming a high-protein diet, proteinuriawas unchanged following 12 weeks of creatine supplementation (1).
  • SodiumSodium: In humans, creatine supplementation, in the heat, resulted in no significant alterations in sodium, potassium, or creatinine excretion rates obtained from 24-hour and exercise urine collection periods (111). In resistance-trained subjects consuming a high-protein diet, electrolytes were unchanged following 12 weeks of creatine supplementation (1).
  • Vitamin AVitamin A: In humans, creatine plus vitamin supplements may lower homocysteine to a greater extent than vitamin supplements alone (333). Creatine may lower the effectiveness of vitamins A, D, E, and K.
  • Vitamin DVitamin D: In humans, creatine plus vitamin supplements may lower homocysteine to a greater extent than vitamin supplements alone (333). Creatine may lower the effectiveness of vitamins A, D, E, and K.
  • Vitamin EVitamin E: In humans, creatine plus vitamin supplements may lower homocysteine to a greater extent than vitamin supplements alone (333). Creatine may lower the effectiveness of vitamins A, D, E, and K.
  • Vitamin KVitamin K: In humans, creatine plus vitamin supplements may lower homocysteine to a greater extent than vitamin supplements alone (333). Creatine may lower the effectiveness of vitamins A, D, E, and K.