Case report · Medicine · 2022Conflicts declared

Chaga mushroom powder linked to kidney injury in one man

What it found

A 69-year-old man who took 10 to 15 g of Chaga mushroom powder daily for 3 months developed acute kidney injury with nephrotic syndrome.

His kidney function recovered after dialysis and high-dose steroids.

What they found

Studies in people

Kidney injury after Chaga

The man developed acute kidney injury with nephrotic syndrome after taking Chaga mushroom powder for 3 months. His serum creatinine was 6.94 mg/dL on admission.

Biopsy findings

A kidney biopsy showed calcium oxalate crystals in the tubules, focal acute tubular injury, interstitial fibrosis, and tubular atrophy. Electron microscopy showed effacement of the foot processes in podocytes.

Treatment and recovery

His kidney function did not improve with hydration and blood pressure control, so he received hemodialysis and high-dose steroids. One month after treatment started, his kidney function recovered and the minimal change disease fully remitted.

Vitamin C also taken

The man also took vitamin C at 500 mg per day for the same 3 months. The paper does not separate the effects of the mushroom and the vitamin C.

What the authors conclude

“In cases of AKI with an unknown cause, it is therefore important to closely examine the patient's medication history, and actively perform a kidney biopsy.”
Kwon O, Kim Y, Paek JH, et al, 2022

Also in their conclusions

  • They advise that in cases of acute kidney injury with an unknown cause, it is important to closely examine the patient's medication history and actively perform a kidney biopsy.
  • They recommend administering high-dose steroids to the patient.
  • They say further research is needed to clarify the disease course of Chaga mushroom-induced oxalate nephropathy.

How it was done

Chaga mushroom is popular in folk medicine for its vitamins, nutrients, and anti-inflammatory and antioxidant effects. Recent studies have reported that taking too much Chaga mushroom can cause acute oxalate nephropathy.

They reported one case: a 69-year-old Korean man who took Chaga mushroom powder at 10 to 15 g per day for 3 months and vitamin C at 500 mg per day. He was treated with hemodialysis and high-dose steroids, and followed for 1 month.

What it can’t tell you

  • This is a single case report, so it cannot show that Chaga mushroom causes kidney injury in everyone.
  • The man also took vitamin C, so the paper cannot tell whether the mushroom alone was responsible.
  • The authors could not determine the urinary oxalate concentration after 24 hours, and did not perform an additional biopsy after treatment.

The paper

Title
Chaga mushroom-induced oxalate nephropathy that clinically manifested as nephrotic syndrome: A case report
Type
Case report
Evidence
Studies in people
Summarised from
Full text
Cite
Kwon O, Kim Y, Paek JH, et al (2022). Chaga mushroom-induced oxalate nephropathy that clinically manifested as nephrotic syndrome: A case report. Medicine. doi:10.1097/MD.0000000000028997Free full textPubMed 35451393DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error