Mrs. M presented with a listing of 20 natural supplements that she was taking to boost her immune organisation and fight off a lingering fatigue attributed to Lyme disease.  She was in nephrology clinic to evaluate a 30% decline in kidney function over the recent three months.

She got straight to the indicate.  "Are the supplements hurting my kidneys?"  The best answer I could come up up with was: "Maybe".  Which led to a give-and-take near why side furnishings can happen with herbal or other dietary supplements:

  • Metabolism of any drug or supplement involves several enzymatic pathways.  Due to genetic variability, an individual may not be able to metabolize a sure supplement, and accumulation of byproducts leads to off-target effects.  As an instance, the "Asian affluent" after booze intake is due to deficiency of acetaldehyde dehydrogenase, a central enzyme needed to break down booze in the trunk.  The resulting acetaldehyde accumulation causes facial redness, headache, and heart palpitations.
  • Supplements contain more than only the pure natural production.  Excipients (inactive 'other ingredients') are added to serve as filler, flavoring, blanket, preservative, etc.1 The inactive ingredients would typically pose little to no wellness chance, nonetheless, again due to genetic variability some people feel side effects.  For example, potassium sorbate is sometimes used to prolong the shelf life of herbal products; sensitivity to this compound induces nausea and tummy cramps.
  • The optimal beneficial dose of many natural supplements is unknown.  Any supplement taken in backlog will overwhelm metabolic pathways and issue in toxicity.  Of note, many herbal products evolved as plant defenses confronting being eaten by insects or animals,ii thus large amounts can be viewed every bit natural poisons.
  • In the setting of liver or kidney disease, byproducts tin accumulate and cause adverse furnishings.
  • Interactions with prescribed medications tin be problematic.  One example is St. John's wort which is consumed for its anti-anxiety and anti-inflammatory properties; this herb is known to inhibit warfarin and thus increases clotting risk in patients on warfarin anticoagulation.

The use of herbal supplements is growing.  In a national U.S. survey of approximately 26,000 people, more than one-third of respondents reported using herbal supplements.iii Older historic period and college educational activity were associated with higher use of herbal supplements.

Even vitamins or minerals, when over-supplemented, can crusade problems.  The recommended daily vitamin C intake is ninety mg for men and 75 mg for women; these needs are easily met by a balanced nutrition.  Many people take vitamin C (ordinarily 1000 mg daily) to boost the allowed organization.  Vitamin C supplementation in men is associated with increased kidney stones,iv likely due to increased urine levels of oxalate (a metabolite of vitamin C) and formation of calcium oxalate stones.  Vitamin D calcium combination supplements, unremarkably taken for prevention of bone fractures, are besides associated with increased risk of kidney stones5 as high body calcium levels leads to high urine calcium.  Information technology is interesting to annotation that the prevalence of kidney stones in the U.S. increased from i in 20 persons to 1 in 11 persons in the by ii decades (NHANES information from 1994 and 2007-2010).6 One wonders if this tendency is partly driven past use of vitamin and mineral supplements.

Research is ongoing to examine how natural supplements can be used to derive health benefits without causing impairment.  For example, our group and other researchers are investigating the antioxidant furnishings of curcumin derivatives (from the spice turmeric) in kidney disease.7 Studies in cancer cell lines discovered that curcumin at high concentrations has a paradoxical consequence of increasing oxidative stress (overwhelming the antioxidant benefits), emphasizing the importance of correct dosing to avert damage.

So what is the best approach if you take decided to take a natural supplement?  Definitely allow your dr. know and then that the medication listing is checked for potential interactions and blood tests can be monitored (if necessary).  Avoid taking amounts in backlog of the manufacturer's instructions.  If you have chronic kidney disease, herbal supplements should be avoided per National Kidney Foundation recommendations8 (until more data is available) given concerns for loftier potassium or phosphorus content, diuretic effects, or direct kidney toxicity.

In the case of Mrs. Yard, she decided to quit the xx natural supplements and her kidney function returned to normal a few weeks later on.

Suggested reading:

1. Natural Healthy Concepts web log on inactive ingredients in supplements (2014).
two. Advances in Diet review newspaper nearly herbal extracts that evolved as establish defenses against herbivores and insects (2011).
iii. Periodical of Patient Experience report on prevalence of herbal supplements use in the U.Due south. (2017).
four. JAMA Internal Medicine report of increased kidney stones in Swedish men taking vitamin C supplements (2013).
five. JAMA meta-analysis noting increased incidence of kidney stones in persons taking vitamin D with calcium (2018).
half-dozen. European Urology article reporting increasing occurrence of kidney stones in the U.S. from assay of National Health and Nutrition Examination Survey data (2012).
7. PubMed list of published enquiry papers about curcumin effects in kidney disease (equally of April 2018).
8. National Kidney Foundation website advising against use of herbal supplements in chronic kidney illness patients (2015).

Wei Ling Lau Headshot
Wei Ling Lau, MD is Assistant Professor in Nephrology at University of California-Irvine, where she studies vascular calcification and brain microbleeds in chronic kidney disease. She is currently funded by an AHA Innovative Research Grant, and has been a speaker for CardioRenal University and the American Society of Nephrology.