As shown in Table 2, supplementation with Sp resulted in around 7% higher hematocrit (HCT) and 15.6% lower platelet (PLT) compared to the control group. Meanwhile, Lym% in the intervention group was significantly different from the control group (p = 0.03).

In terms of within-group analysis, both groups exhibited a reduction in levels of ESR and international normalized ratio (INR) (p < 0.05). However, only the Sp group demonstrated a significant decrease in prothrombin time (PT) and partial thromboplastin time (PTT). Furthermore, in contrast to the decrease observed in serum Hb and RBC in the control group over a period of 2 weeks, these values remained unchanged in the intervention group.

Regression analysis showed that Sp supplementation could significantly improve some of the biochemical laboratory characteristics of COVID-19 patients (Table 3). In comparison with the control group, BUN and LDH were 21.6% and 20.8% lower in the Sp-supplemented group, respectively. Meanwhile, supplementation led to elevated levels of serum protein and albumin in the intervention group when compared to the control group (p = 0.05). On the final day of supplementation, the serum zinc level in the Sp group was 19.8% higher than that in the control group, with a corresponding p value of 0.01. BAR value was significantly lower in the intervention group compared to the control group (8.34 vs. 5.60,p = 0.01).

Within-group analysis also indicated that phosphorus, magnesium, and selenium levels improved considerably in Sp patients (p < 0.05). Taking supplements in patients of the intervention group resulted in a significant reduction in LDH levels and a noteworthy increase in albumin levels. As a result, the difference between the control and the Sp group was statistically significant.

The regression analysis did not reveal any significant differences between the groups in terms of tested immunological and hormonal characteristics (p > 0.05) (Table 4).