Pneumonia is one of the major causes of childhood death. Many factors have an impact on the pathogenesis and clinical course of pneumonia. We targeted to evaluate the effect of serum iron, vitamin D, and zinc deficiency and identify the most related nutrient deficiency to pneumonia.
In our study, we evaluated the iron profile and the possible impact on pneumonia. We found that 64.5% of cases had hemoglobin level < 11gm/dl which might indicate a strong association between iron deficiency anemia and the CAP. El-Sakka et al. stated that a low hemoglobin level is a risk factor for acute lower respiratory infections as it was detected in 62.5% of pneumonia patients [13]. Similarly, Hussain et al. reported that 64.5% of their hospitalized patients and 28.2% of the healthy controls were anemic and that the anemic children were 4.6 times more susceptible to lower respiratory tract infection [14].
In the current study, there was no relation between hemoglobin level and the severity of pneumonia (Table 6). In contrast, Coles, Malla, and Shallans’ studies reported an association between low hemoglobin levels and pneumonia severity [15,16,17].
In our study, there was no association between serum iron level and community-acquired pneumonia; however, the TIBC was more in the pneumonic group. Although these findings may be against the physiological facts during infection, yet maybe the small sample size and other causes of anemias had an effect. (Table 3)
Vitamin D was significantly lower among the patient group than in the control group (Table 4). Vitamin D levels correlated with the severity of pneumonia in the studied population (Table 6). Kulkarni and Chougule as well as Jovanovich et al. reported that there was a high association between vitamin D deficiency and community-acquired pneumonia in pediatrics [18, 19].
A study noted that 74% of children with severe pneumonia had rickets as defined by low or normal calcium, low phosphorous, and high serum alkaline phosphatase [20]. Even subclinical vitamin D deficiency was found to be associated with severe acute lower respiratory infection in children less than 5 years of age [21]. The association of vitamin D deficiency and lower respiratory tract infections is not only limited to children but is also found among newborns, infants, and adults [22].
Zinc level was significantly lower in the patient group than in the control group which means that inadequate serum zinc level is associated with community-acquired pneumonia (Table 5). A study reported that the zinc level in peripheral blood was reduced in 76% of critically ill infants with community-acquired pneumonia [23]. Barnett et al. found that zinc supplementation had a beneficial effect on the clinical course and incidence of pneumonia [24]. Also, Arica et al. demonstrated that there was a significant relationship between the plasma levels of zinc and the susceptibility to pneumonia in children aged 0-24 months; moreover, zinc may be more protective in children whose immune systems are not fully developed [25]. Another study reported that high levels of zinc in pediatric patients with pneumonia could lower the incidence and prevalence of pneumonia, days of hospitalization, and improve the clinical outcome [26].
In contrast, Saleh et al. reported that there is no relation between zinc levels and community-acquired pneumonia [27]. Also, on the contrary, Vinayak and Behal found that a course of zinc supplementation for patients with pneumonia, aged up to 5 years, did not have a significant effect and recommended that it should not be proposed for adjuvant therapies and so no relation between serum zinc level and pneumonia [28].
We found that serum vitamin D is the most important single relative risk factor for acquiring CAP in comparison to the zinc level followed by TIBC (Table 8).
The results of the current study are limited by the small sample size, short duration of follow-up, and the lack of age subgrouping. Further studies are recommended to ensure the accuracy of our findings.
