Lactic acid

Elevated by a number of nonspecific influences, such as vigorous exercise, bacterial overgrowth of the GI tract, shock, poor perfusion, B-vitamin de ciency, mitochondrial dysfunction or damage, and anemia, among others. Tiglylglycine is a more specific indicator of mitochondrial dysfunction or damage. The possibility of an inborn error of metabolism increases when the lactic acid value exceeds 300 mmol/ mol creatinine. There are many inborn errors of metabolism that are present with elevated lactic acid, including disorders of sugar metabolism, pyruvate dehydrogenase de ciency, and mitochondrial disorders.

Possible causes:

- Hypoxia and/or zinc deficiency

- Metabolic stress (e.g. alcohol, toxic metal exposure, or anaemia)

- Possibly insignificant when pyruvic acid is also high

Additional investigations:

- Iron Studies & Red Cell Zinc

- Comprehensive Urine Elements Profile

- Functional Liver Detoxification Profile

Treatment considerations:

If pyruvate NOT high:

- Correct hypoxia

- Remove metabolic stress

- Correct anaemia

- Zn, CoQ10, B2, B3

Lactate is formed from pyruvate in anaerobic or oxygen starved (hypoxic) circumstances to allow for ongoing production of ATP in these anaerobic conditions. There are no known clinical problems associated with low lactic acid. Low levels are usually a result of reduced amounts of its precursor, pyruvic acid.

Lactic acid is a microbial metabolite, urinary lactic acid is produced by Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter, Acinetobacter, Proteus mirabilis, Citrobacter frundii, Enterococcus faecalis, Streptococcus group B, Staphylococcus saprophyticus, Bacillus, Corynebacterium, Rhizopus and Saccharomyces cerevisiae. Lactic acid is a good marker distinguishing lower urinary tract infection (cystitis) from upper urinary tract urinary tract infections (pyelonephritis). Excess of exercise, bacterial overgrowth in the GI tract, B-vitamin deficiency have been shown to be contributing factors. The possibility of an inborn error of metabolism increases when the lactic acid value exceeds 300 mmol/mol creatinine. There are many inborn errors of metabolism that are present with elevated lactic acid, including disorders of sugar metabolism, pyruvate dehydrogenase deficiency, and mitochondrial disorders.