1.
Overview and Significance in the body
Citric acid is an intermediate in the Citric Acid Cycle (TCA, or Kreb's Cycle) in the mitochondria and is synthesized in the first step via the combination of oxaloacetate and Acetyl-Coa via Citrate Synthase (to produce Citrate).[1][2] It is the first step of the TCA cycle, but not the rate limiting step (which is the decarboxylation step of isocitrate dehydrogenase, or step 5).
2.
Citric Acid and Acidity/Alkalinity
Citric acid is commonly supplemented as an aims to reduce body acidity, it has once been hypothesized that an acidic diet leeches alkaline minerals from bone to counteract changes in body acidity, thus reducing bone mass (as most minerals deposited in bone are alkaline in nature).[3]
In regards to bone metabolism, one study found that low (0.72g) and high (2.16g) dose potassium citrate supplementation has not been shown to have a significant effect on reducing the effects of osteoporosis and the loss of bone turnover in and of itself[4] although it seems to be able to ameliorate calcium losses induced by a high sodium intake.[5] Another short-term study, using much higher doses (0.1g/kg bodyweight) found beneficial effects on bone metabolism as judged by urinary excretion.[6]
References
- ^Srere PAThe molecular physiology of citrateCurr Top Cell Regul.(1992)
- ^Beeckmans SSome structural and regulatory aspects of citrate synthaseInt J Biochem.(1984)
- ^Wachman A, Bernstein DSDiet and osteoporosisLancet.(1968 May 4)
- ^Macdonald HM, Black AJ, Aucott L, Duthie G, Duthie S, Sandison R, Hardcastle AC, Lanham New SA, Fraser WD, Reid DMEffect of potassium citrate supplementation or increased fruit and vegetable intake on bone metabolism in healthy postmenopausal women: a randomized controlled trialAm J Clin Nutr.(2008 Aug)
- ^Potassium Citrate Prevents Increased Urine Calcium Excretion and Bone Resorption Induced by a High Sodium Chloride Diet
- ^Marangella M, Di Stefano M, Casalis S, Berutti S, D'Amelio P, Isaia GCEffects of potassium citrate supplementation on bone metabolismCalcif Tissue Int.(2004 Apr)
- ^Teucher B, Olivares M, Cori HEnhancers of iron absorption: ascorbic acid and other organic acidsInt J Vitam Nutr Res.(2004 Nov)