Supplemental Vitamin & Kidney Stones

Case: 53 years old male who recently became conscious of his health, and started taking multiple different vitamins, after subscribing to health-related social media videos, is admitted to the ICU with severe sepsis and flank pain associated with crepitus over the same area. The patient gets diagnosed with severe emphysematous pyelonephritis. Which of the following 'over the counter' (OTC) vitamins may cause these symptoms? - select one

A) Vitamin A

B) Vitamin B

C) Vitamin C

D) Vitamin D

Answer: C

Higher than recommended dietary allowance of Vitamin C (ascorbic acid), i.e., 90 mg/day, may lead to the formation of urinary calcium oxalate stones. High-dose vitamin C results in increased oxalate generation as the ascorbic acid is metabolized. For every 1000 mg of vitamin C ingested above 500 mg/day, urinary oxalate excretion rises 6 to 13 mg/day. Ingestion of 2000 mg/day of vitamin C significantly increases urinary oxalate excretion, carrying an extremely high risk of calcium oxalate stone formation. 

This risk appears to be higher in males (Reference #2).

#nephrology

#vitamins

References: 

1. Massey LK, Liebman M, Kynast-Gales SA. Ascorbate increases human oxaluria and kidney stone risk. J Nutr 2005; 135:1673.

2. Thomas LD, Elinder CG, Tiselius HG, et al. Ascorbic acid supplements and kidney stone incidence among men: a prospective study. JAMA Intern Med 2013; 173:386.

3. Ferraro PM, Curhan GC, Gambaro G, Taylor EN. Total, Dietary, and Supplemental Vitamin C Intake and Risk of Incident Kidney Stones. Am J Kidney Dis 2016; 67:400.