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What is the relationship between vitamin D and childhood UTIs?

Posted on: August 7, 2018   by  Rachel Namery & John Cannell, MD


Has your child or others you know ever suffered symptoms (subjective evidence of disease) such as irritability, fever, pelvic pain, crying on urination, poor appetite, vomiting, rapid heartbeat and/or loss of appetite or signs (objective evidence of disease), such as  blood in the urine, cloudy urine, foul-smelling urine, pain, stinging, or burning with urination,  pressure or pain in the lower pelvis or lower back, frequent urination, waking from sleep to urinate,  feeling the need to urinate with minimal urine output or urine accidents after the age of toilet training. These are the vague signs and diffuse symptoms of urinary tract infections (UTIs) in children. UTIs are caused by pathogens, usually bacteria, especially E-Coli, that migrate up the urethra, to the bladder or even kidneys.

Although the aged have the highest rates of this infection, young children are also prone to it. In fact, it is estimated that anywhere between 70,000 to 180,000 children will develop a UTI by the time they are six years old. It is particularly hard to detect among infants, as their only symptom may be fever. UTI’s often recur. If left untreated, they can lead to serious complications, including kidney stones, scarring of the urinary tract, sepsis and death.

Are there ways of preventing childhood UTIs? Yes, don’t give female children bubble baths. As they allow bacteria and soap to enter the urethra, avoid tight-fitting clothing and underwear for your child, especially girls, ensure that your child drinks enough fluids,  avoid allowing your child to have caffeine, which can cause bladder irritation, change diapers frequently in infants, teach older children proper hygiene for maintaining a clean genital area while avoiding over washing, encourage your child pee frequently rather than holding in urine, teach your child safe wiping techniques, especially after bowel movements. wiping from front to back reduces the likelihood that bacteria from the anus will get transferred into the urethra, correct and prevent constipation and avoid unnecessary antibiotics.

In addition, our bodies naturally produce antimicrobial peptides (AMPs), which act as the first line of defense against foreign invaders. There are two main types of AMPs: cathelicidin and defensin, both of which modulate the immune system. These AMPs have proven to be particularly useful for protecting against UTIs.

Urinary tract infections symptoms

The connection between vitamin D and infections

Vitamin D is involved in so many bodily processes, and there is evidence that it is also involved in children’s immune system, both innate (a nonspecific defense system) and adaptive (a specific defense system) immunity. In addition, research has shown that vitamin D upregulates cathelicidin. This may indicate that vitamin D status can help protect against UTIs.

This knowledge has led researchers to theorize that vitamin D may play a role in UTIs among children. A 2015 study found low D levels increase UTI risk among children, and a 2018 study confirmed it. However, until now, the mechanism behind this finding has yet to be studied.

New research on vitamin D and AMPs

A recent study aimed to determine whether either vitamin D status, cathelicidin and B-defensin-2 are associated with urinary tract infections in young children and infants.

A total of 120 children under 3 years of age (median age was 11.4 months) were included in this study; 76 children had urinary tract infections and the remaining 44 children did not.

The children’s serum 25(OH)D, cathelicidin and B-defensin-2 concentrations were measured. All of the children below the age of two were prescribed 10 mcg (400 IU) vitamin D3/day and the children with UTIs were followed for relapses. For the purposes of this study, vitamin D deficiency was defined as serum levels of 25(OH)D < 20 ng/ml, insufficiency was defined as serum 25 OH(D) between 20 and 30 ng/ml and sufficiency were defined as 25 (OH)D >30 ng/ml.

Here is what the researchers found:

  • Most of the infants and young children are deficient or insufficient in vitamin D.
  • Only 25 of the 120 children studied had inadequate vitamin D levels despite supplementing with 10 mcg (400 IU) D3 daily during the first two years of life.
  • Vitamin D status was inversely associated with age (p<0.0001).
  • Vitamin D levels in the female children were significantly lower than the male children (p < 0.01).
  • As for the AMPs, vitamin D status was positively associated with plasma levels of cathelicidin (p<0.01) but did not have a correlation with B-defensin-2 levels (p>0.05).
  • Both cathelicidin and B-defensin-2 levels went down as age increased which indicates lowered immunity.
  • Vitamin D deficiency was associated with an increased occurrence of UTIs among girls (p,0.01).
  • The study also showed that 74% of the UTI cases occurred during the darker and colder seasons in Sweden, perhaps due to lower levels of vitamin D during that time.
  • After further analysis, the UTI group had significantly lower levels of vitamin D (p < 0.0001) along with lower levels of cathelicidin (p < 0.0001) and B-defensin-2 levels (p < 0.0001).
  • There was not a significant correlation between UTI recurrence and vitamin D, cathelicidin and B-defensin-2 levels (p > 0.05).


Vitamin D levels in children are low in many countries around the world. This places children at risk of a variety of health complications and warrants better guidelines on vitamin D supplementation. The findings from this study suggest vitamin D deficiency may contribute to the risk of urinary tract infections in children, especially in females.

Supplementing with vitamin D3 will probably decrease your child’s risk of developing UTIs, perhaps substantially. The VDC recommends maintaining your child’s 25(OH)D levels between 40-80 ng/ml, and we offer, to that end, an easy way to avoid having your childs blood drawn: our in-home vitamin D test. We suggest parents give their infants 25 mcg(1000 IU) and children 25 mcg (1000 IU)/25 lbs. of vitamin D3 daily when they are unable to receive adequate full-body sun exposure, that is, when your shadow is shorter than you are.

If you want a high quality, low cost vitamin D supplement for your child, the VDC recommends you buy it from Bio-Tech Pharmacal; use code “VDCBiotech20” for 20% off your order. Not only will you save money, but you’ll help support the VDC by doing so.


Namery, R & Cannell JJ. Vitamin D association with UTIs in children: is there a link? The Vitamin D Council Blog & Newsletter, 7/30/2018.


Georgieva, V et al. Association Between Vitamin D, Antimicrobial Peptides and Urinary Tract Infection in Infants and Young Children. Acta Paediatr, 2018

1 Response to What is the relationship between vitamin D and childhood UTIs?

  1. profpremrajpushpakaran

    good article!!

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What is the relationship between vitamin D and childhood UTIs?

A new study suggests vitamin D may protect against UTIs among children by upregulating their own naturally occurring antimicrobial peptides.

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