Problematic alcohol use decreases the serum zinc level by 2.7 mcg/dl, and the serum vitamin A level by 1.09 mcg/dl. This finding was in line with previous research outputs [40, 41]. This is because alcohol interferes with the absorption and metabolism of zinc [42]. However, alcohol increases the serum iron level of visceral leishmaniasis patients by 7.6 mcg/dl. This is because alcohol increases the absorption of iron from the intestine [43].
A high dietary diversification score increases the serum zinc level of leishmaniasis patients by 9.75 mcg/dl, the iodine level by 25.84 mcg/l, the serum vitamin D level by 16.24 ng/ml, and the serum vitamin A level by 1.62 mcg/dl. This finding agrees with previous work [44]. This is because high dietary diversification score increases access to enough quality and quantity of micronutrients [45].
A high family size decreases the serum zinc level of the patients by 1.63 mcg/dl, the serum iron level by 5.14 mcg/dl, the serum zinc level by 11.36 ng/dl, the serum vitamin A level by 5.03 mcg/dl, the serum vitamin D level of the patients by 1.15 ng/ml. This finding was in line with previous researches work [46-48]. This is due to the sharing of the limited micronutrient-rich foods to the unbalanced household family members [49].
The serum zinc level of HIV positive visceral leishmaniasis patient was 2.95 mcg/dl less than HIV negative visceral leishmaniasis patients, HIV positive visceral leishmaniasis patients had 5.54 mcg/dl less serum iron level than HIV negative visceral leishmaniasis patients, HIV positive visceral leishmaniasis patient had 18.1 ng/dl less serum selenium level than HIV negative visceral leishmaniasis patients, HIV decreases the iodine level of visceral leishmaniasis patients by 38.02 mcg/l, the serum vitamin A level of visceral leishmaniasis patients by 2.89 mcg/dl, the serum vitamin D level by 9.43 ng/ml. This finding agrees with previous research findings [21, 50]. This is due to the reason that HIV infection reduced the intake of food and absorption and increased utilization and loss of micronutrients [51].
Chronic illness decreases the serum iron level of visceral leishmaniasis patients by 7.44 mcg/dl, the iodine level by 5.14 mcg/l, and the serum vitamin A level by 2.56 mcg/dl. This finding agrees with the 2019 published research work [52]. This is because the homeostasis of micronutrients, especially iron will be disturbed by chronic illnesses [53].
Malaria co-infection decreases the serum iron level of visceral leishmaniasis patients by 12.69 mcg/dl, the iodine level by 3.78 mcg/l, the serum vitamin A level by 4.8 mcg/dl and the serum vitamin D level by 0.61 ng/ml. This finding was in line with previously published works [54-56]. This is due to the ingestion of the nutrients by the parasites, decreases the intake from the host (anorexia), and increases the execration of the nutrients [57-59].
Hookworm infection decreases the serum iron level of visceral leishmaniasis patients by 4.48 mcg/dl; the serum vitamin D level by 3.94 ng/ml. This finding agrees with previous research outputs [60]. This is due to ingestion of nutrients by the parasites [61].
Per a year increase in the age of the patient, the serum iron level increases by 0.11 mcg/dl. This finding agrees with other’s scholars work [62]. This is due to the fact that serum iron decreasing factors like chronic diseases and other unhealthy lifestyles were prevalent in the older age [63].
Per a centimeter increase in the MUAC of the patient, the serum iron level increases by 0.75 mcg/dl and the serum vitamin A level by 0.86 mcg/dl. This finding was in line with previously published work [64]. This is due to the reason that, higher MUAC groups have good nutritional support [65].
Smoking decreases the iodine level of visceral leishmaniasis patients by 12.34 mcg/l. This finding agrees with previous scholar’s work [66]. This is due to the effect of smoking in disturbing the iodine metabolism [67, 68].
Leishmaniasis patients in the urban area had 0.81 mcg/dl higher serum vitamin A level than the rural patients. This finding agrees with finding from Nepal [69]. This is because of the higher awareness of the urban population about vitamin A [70].
A unit increase in the BMI of visceral leishmaniasis patients increases the serum vitamin D level by 1.52 ng/ml. This finding disagrees with finding from Norway [71]. This might be due to the cultural difference between the two populations.
The serum zinc level of females was 1.28 mcg/dl less than male. This finding agrees with previous literature [72]. This is because women lose their serum zinc level during their pregnancy and menstruation [73].
The anti-leishmaniasis treatment did not increase the serum zinc, vitamin A, vitamin D, or iron level of the patients. It increases the serum selenium level by 3.04 ng/ml and the iodine level by 13.67 mcg/l.
The overall treatment success rate of visceral leishmaniasis treatment was 84.7 % [95 % CI: 82.77 % - 86.67 %]. A systematic review and meta-analysis estimate also supports this finding [74].
Low serum zinc level decreases the treatment outcome of visceral leishmaniasis. This finding was in line with finding from India [75]. This is due to the effects of zinc in the immune system of the patients [76].
Higher patient iron level increases the treatment success rate of visceral leishmaniasis. This finding supports the results of previously published work [77]. This is due to the crucial role of iron in red blood cell production that is used to transport essential substances, including the anti-leishmaniasis drugs[78].
Higher serum vitamin A and Vitamin D level favors good treatment outcome in visceral leishmaniasis. This finding agrees with previous researchers outputs [79-81]. This indicates that administering the anti-leishmaniasis treatment alone will not yield a favorable treatment outcome in visceral leishmaniasis patients.
Possible limitation of this study was a failure to address all the vitamins and minerals status of visceral leishmaniasis patients, but since practically it is very difficult to address all of them this study gives the baseline evidence on main vitamins and mineral levels.