Vitamin D for Acute Otitis Media

Possibly in children who already get repeated ear infections, but it is not established. In the only randomised trial found for this page, 116 children with recurrent acute otitis media (3 or more episodes in the previous 6 months, or 4 or more in 12) took vitamin D 1,000 IU a day or placebo for 4 months and were followed for 6. At least one ear infection occurred in 26 of 58 children on vitamin D and 38 of 58 on placebo (P = 0.03). The authors also report a difference in uncomplicated ear infections (P < 0.001), but no difference in the number of children with spontaneous ear discharge.

Everything around that trial is weaker or points the other way. Some studies find lower vitamin D levels in children with ear infections, but a 2016 meta-analysis found no association between vitamin D level and overall otitis media risk, and a Nepalese study found no difference. Large trials of higher doses in young children did not reduce infections, and the 2019 Italian Society of Pediatrics prevention guideline states that vitamin D is not recommended for preventing acute otitis media. Treat vitamin D as an unproven add-on to the standard steps, not a replacement.

A 2019 review of vitamin D and otitis media proposes three routes: vitamin D may raise antimicrobial peptides that act against ear pathogens and biofilm formation, support a less inflammatory immune response, and favour beneficial commensal bacteria. The trial's authors report that low vitamin D was common in children with recurrent ear infections, and that ear infections were more frequent when blood 25(OH)D was below 30 ng/mL.

These are proposals, not measured effects in the middle ear. A 2024 Chilean trial in 303 preschoolers raised vitamin D levels with weekly doses equivalent to 800 and 1,600 IU a day, yet found no difference in the change in cathelicidin (an antimicrobial peptide, also called LL-37; P = 0.30) or in the number of respiratory infections (P = 0.85). A Toronto trial raised children's 25(OH)D to 48.7 ng/mL on 2,000 IU a day and still saw no fewer viral upper respiratory infections than on 400 IU.

The link between low levels and infection is also open to the reverse explanation: children who are ill often differ from healthy ones in other ways, and comparisons of blood levels cannot show which came first.

The trial gave 1,000 IU (25 mcg) of vitamin D a day for 4 months. Its authors report that this amount restored 25(OH)D to 30 ng/mL or more in most children. The abstract does not give the children's ages, the form of vitamin D or their starting levels, so the table below shows what was tested, not what to give. The 30 ng/mL target is higher than the 20 ng/mL that the NIH Office of Dietary Supplements (ODS) describes as sufficient for most people.

For scale, ODS lists the recommended intake as 400 IU a day for babies up to 12 months and 600 IU for ages 1 to 18, with upper limits from 1,000 IU a day (0 to 6 months) to 4,000 IU (age 9 and up). The trial dose is therefore at the upper limit for a baby under 6 months and within it from 7 months. ODS also notes that the American Academy of Pediatrics recommends 400 IU a day for breastfed infants.

The 2013 trial randomised 116 children with a history of recurrent acute otitis media to vitamin D 1,000 IU a day or placebo for 4 months, with episodes monitored for 6 months. Fifty-eight children were in each group. The number of children with at least one ear infection was lower on vitamin D (26 versus 38; P = 0.03), with a marked difference in uncomplicated infections (P < 0.001). Spontaneous ear discharge did not differ. Within the study, ear infections were less likely in children whose blood levels reached 30 ng/mL or more, but that comparison depends on who reached that level and is not itself randomised.

Limits: it is small, the abstract does not give the children's ages or starting levels, it does not report side effects, and it tested children who were already prone to infections. No trial in the sources reviewed tested whether it prevents a first ear infection.

Several studies compared blood levels in children with and without ear infections. One study of 84 children aged 1 to 5 with recurrent otitis media and 108 healthy children found mean 25(OH)D of 11.4 versus 29.2 ng/mL; the children with low levels were then given vitamin D with no comparison group, so the few attacks that followed over a year cannot be credited to vitamin D. A second study, in Erzurum, Turkey (88 children with acute otitis media, 81 controls), found 20.6 versus 23.8 ng/mL. A Colombian cohort of 475 school-age children found that vitamin D deficiency was associated with more days of earache or discharge with fever (adjusted incidence rate ratio 2.36, 95% CI 1.26-4.44). A 2025 Romanian cross-sectional study of 118 children also found lower levels in children with otitis media, though its very large effect estimates (odds ratio about 120) are not credible as the effect of one risk factor.

The picture is not consistent. A Nepalese study of 60 children with acute otitis media and 60 controls found nearly identical levels (22.12 versus 22.58 ng/mL; p = 0.737), and a 2016 meta-analysis of 5 studies and 16,689 people found lower levels in those with otitis media (weighted mean difference -5.67; 95% CI -8.08 to -3.26) but no association between vitamin D level and otitis media risk (OR 0.80; 95% CI 0.47-1.38). Its subgroup analysis suggested lower levels in acute but not chronic otitis media.

These trials measured infections in general (respiratory infections, or parent-reported infections of any type), and none reports ear infections separately in its abstract. The BMJ analysis covers all ages. A 2017 BMJ analysis of individual data from 25 trials (11,321 people aged 0 to 95) found fewer acute respiratory infections overall (adjusted OR 0.88, 95% CI 0.81-0.96), with the benefit seen in daily or weekly dosing (0.81) but not bolus doses (0.97) and mostly in people with very low baseline levels (below 25 nmol/L; 0.30).

The pediatric trials are less encouraging. In 703 Toronto children aged 1 to 5, 2,000 IU a day did not reduce laboratory-confirmed viral upper respiratory infections compared with 400 IU (rate ratio 0.97, 95% CI 0.80-1.16). In 975 Finnish infants, 1,200 IU versus 400 IU a day gave the same parent-reported infection rate (rate ratio 1.00, 95% CI 0.93-1.06). In 303 Chilean preschoolers, weekly vitamin D did not change the number of respiratory infections. A 2026 Cochrane review of 107 trials in 31,521 pregnant women and young children found low-certainty evidence of a slight reduction in healthcare visits for respiratory infection (RR 0.95, 95% CI 0.91-1.00), and moderate-certainty evidence that higher doses were no better than lower ones (RR 0.94, 95% CI 0.81-1.10).

Missing from the record: a second randomised trial of vitamin D in otitis-prone children, any trial in children without recurrent infections, any trial of vitamin D as a treatment for an active infection, and follow-up beyond 6 months. Observational data cannot settle whether raising vitamin D lowers risk, and the broader respiratory trials do not isolate ear infections.

For comparison, xylitol has more trials for the same condition, with mixed results, and the same Italian guideline does not recommend xylitol, probiotics or vitamin D. For vitamin D and infections more generally, see the recurring infections page.

The ear infection trial's abstract does not report side effects, so its tolerability is unknown from that source. Across other trials, a 2026 Cochrane review found hypercalcaemia (high blood calcium) infrequent in young children given vitamin D, with very low-certainty evidence of little to no effect on its risk (RR 0.81, 95% CI 0.53-1.24), and the Chilean preschool trial found no difference in adverse events (P = 0.41).

The real risk is too much. NIH ODS states that vitamin D toxicity causes hypercalcaemia and, in extreme cases, kidney failure and soft-tissue calcification; it is almost always the result of excessive supplement intake, and has followed manufacturing errors and inappropriate or excessive dosing. Calcium supplements taken with vitamin D may raise the risk of certain adverse effects. Signs of too much vitamin D, through high blood calcium, include nausea, vomiting, muscle weakness, loss of appetite, dehydration, excessive thirst and urination, and kidney stones. If a child on a supplement shows these, stop it and call the clinician. Age-based upper limits apply (see the dosing table).

NIH ODS lists a few medicines that interact with vitamin D, and anyone taking regular medicines should discuss vitamin D with the prescriber. The more likely problem for a family is substitution: vitamin D has not been shown to treat an ear infection, so it should never delay seeing a clinician for ear pain, fever or discharge.