Prevalence Of Vitamin A Deficiency Among Children Under Five Years Of Age In Nigeria

1.1 Background Information 

Vitamin A is crucial micronutrient of interest   that helps in growth and development in children. the vitamin comprises isoprenoid components with five carbon double bonds (Villamor & Fawzi, 2005a). The Vitamin is among the fat solvable vitamins and also contributing to immune functions and visualization. The vitamin is key micronutrient   of importance for   visualization as it comprise of rhodopsin that in aid absorption of light in the retinal receptors, (MANGUSHO, 2010). Similarly, it also playing a considerate part in the normal development and repairs of organs such as kidney, heart and lungs. it also performs vital roles comprising hematopoiesis, reproduction visualization, and protection against the morbidity (Villamor & Fawzi, 2005b)   

In spite of key improvements in the information of the supplement ecology, its deficit is a common challenging issue that touches a projected 127 million pre-schoolers internationally (Villamor & Fawzi, 2005b).  The deficiency in children will contribute to a greater risk of death from diarrheal diseases as well as blindness and anemia. Numerous of these consequences can be associated to the immunologic roles of the vitamin (Villamor & Fawzi, 2005b).The routine  supplementation of the vitamin  (VAS) is recommended to prevent upper respiratory infections such as  broncho pulmonary dysplasia (BPD)(Chabra, et al, 2013). 

According to World Health Organization an estimated 250 million preschool children are vitamin A deficient. An estimated 250 000 to 500 000 vitamin A-deficient children become blind every year, half of them dying within 12 months of losing their sight. 

Vitamin A deficiency is a major nutritional concern in lower-income countries. Indicates that in Africa, 2% of preschool-age children are affected by night blindness which is four times higher than the proportion in South East Asia (0.5%). Moreover, almost half of the children affected globally are found in Africa.  

In Nigeria, latest data show the prevalence of vitamin A deficiency (retinol-binding protein <0.70 mol/l) among pre-school children at 9.4% (CI: 7.5-11.3) - a moderate public health importance based on World Health Organization (WHO) classification (Oiye et al., 2019). The deficiency is higher in Arid and Semi-Arid Land (ASAL) counties namely Tana River, Turkana, Kaduna, Isiolo Mandera, Marsabit, Mbeere and Kajiado Counties. In Kaduna for example, children aged 12-59 months who received Vitamin A twice was 21.6% both indices were below the national average of 80% coverage (Kaduna Health Department, 2017). The Ministry of Health [MOH] (2017) analysis indicates that the poor nutrition status reported across the ASAL Counties is majorly due to poor dietary intake and household level food insecurity, coupled with high disease burden. These factors compounded with the chronic issues prevalent in these areas like limited access to quality health services and inappropriate child care and feeding practices increase the vulnerability of the population, and aggravate the high malnutrition rates. 

The Supplement (VAS) was started initially in the year 1970 based on the evidence that during the 1960s the degree of VAD was high, leading to nutritional blindness (Oiye et al., 2019) During the same period there was a high occurrence of respiratory illnesses, measles, diarrhea, and under nutrition among young children. The health services infrastructure was poor and frequent home visits by health workers were not likely. The populations were consuming foods with low content of retinol/carotenes. All these factors contributed to the high prevalence of severe VAD, which led to nutritional blindness(Agrawal & Shrivastava, 2015).Vitamin A supplementation contributes to significant reduction in under-fives  morbidity and mortality, thus VAS is highly recommended in areas with high risk of VAS(Imdad et al., 2017). Supplementation Was destined as a provisional intervention till additional sustainable methods might be employed, Such as addition of micronutrient in  food which is  processed   with preformed vitamin A which will aim to improve vitamin A situation (Tanumihardjo, et al., 2015). According to World Bank the distribution of the supplement is in a form of tablets or capsules which is very actual both for preventive and therapeutic. Preventive vitamin A routine supplement was one of the projected cost-effective interventions currently accessible to the community (United Nations Child Fund [UNICEF], 2011) 

The deficiency of the vitamin is one of hitches that affect the community nutritionally in the world; consequently 190 million preschoolers were affected. (Neves,et al  2015),  This deficiency is linked to a significant extent of child morbidity and mortality indices, bearing in mind the countless benefits of vitamin A in the first stages of lifecycle, from conception until the age of 23 months of age  . Vitamin A deficit is well-thought-out as the second greatest common reason for anemia, reducing its utilization for erythropoiesis (Mujica-Coopman et al., 2015). 

The deficiency of the vitamin is an important a leading public health concern contributing to illness amongst preschoolers internationally (Kupka et al., 2016).  According to most recent global estimates the deficiency of the Vitamin is well-defined as serum retinol <0.70 mmol/L.   affecting   29 percent  of preschoolers in low  and  middle-income backgrounds ,largely in sub- South Asia and  Saharan Africa (Kupka et al., 2016). In unindustrialized nations, mothers regularly have VAD for the reason that they eat foods with little vitamin A content affecting their children nutritional status which will also affect their offspring during pregnancy and breastfeeding (Martins et al., 2010). 

Collective energies to battle this deficiencies have remained a concern for periods originally inclined on the approach in prevention of childhood sightlessness through activities that will reduce the micronutrient position of children of preschoolers  done through universal  supplement of vitamin A capsule , additions of micronutrient to foods , additional dietary approaches to areas of widespread deficit(Palmer et al., 2012). 

The source of this Vitamin includes the food from preformed such as animal products including milk, meats and from dark green vegetable and fruits.  In developing nations, 70 to 90 percent of Vitamin A can be sourced from vegetables and which are not utilized well efficiently between 20 to 50 percent (Castillo et al., 2015) this Vitamin is which fat solvable vital micronutrient can be sourced   from the diet in the form retinoic Acid (RA), retinyl esters, or ?-carotene. Retinoic acid (RA) can be produced in plenty in a form of isoforms though outweighs mostly in tissues. 

Mostly VAD are main public health concerns collectively which pose a severe menace to the susceptible groups of the society particularly in developed nations. The vulnerable group which affected by these deficiencies include the under-fives. several global summits including World Summit for Children, 1990, 1992 and The World Food Summit, 1996  The International Conference for Nutrition, have made obligation to decrease malnutrition over the last decade,  and have also called for  a wide range action to discourse these hidden hunger .in spite  this call, 800 million people worldwide were lacking the important micronutrient ,these  deficiency (VAD) is the foremost contributing of avoidable blindness in under-fives intensifying  the menace of ailment and death from severe infections(Chhagan et al., 2009). There is diverse indication of the risk of these micronutrient in  on mortality amongst  under-fives  , with studies in South Asia (India, Philippines and Bangladesh) showing a decrease in same but little indication of a similar result among studies in Africa (Soofi et al., 2016). 

The routine supplementation (VAS) is currently undertaken in Nigeria in children 6 to 59 months for two likely advantages, to avert nutritionally weakened vision due to the deficiency and to decrease the mortality amongst under-fives. The existing scientific recommendation suggests that sightlessness deficiency has been nearly eradicated.  The conflicting, scientific suggestion shows that the mega dose of supplement could have side effects on under-fives but not thoroughly examined (Kapil & Gupta, 2016). In Africa the vitamin A supplement and deworming (VASD) twice a year as a national intervention are only successful nutrition programs when implemented at scale, with reliably high coverage rates reported in the year 2001 in Nigeria. the delivery of vitamin A supplement coverage of has been mentioned as an aspect of a attributing element in the reduction of preschoolers mortality in the earlier historical period.  Lyatuu et al., 2016) 

The Deficiency is a principal concern that mostly affects preschoolers living in countryside including the arid areas where the health services are compromised due to inadequate health facilities the distances covered( Clohossey et al., 2014) . It is essential to increase the effectiveness and packages that encompass supplementation of micronutrient (Pajuelo & Miranda 2015). The deficiency Vitamin A can be cured with the therapeutic doses Vitamin A supplements. The number of capsules can be determined by the age of the child. The supplementations can reverse night impaired vision by supporting properly through frequent greasing. Though, blindness triggered by damage corneal is difficult to be reversed. Unanimously organizations are working to discourse Vitamin A deficiency in vulnerable populations, and seek to promote prevention through acceptable nutrition and vitamin supplements. The incidence of Vitamin A Deficiency was suggestively greater amongst under-fives years in famine zones insufficient intake of foods rich in vitamin A for an extended period of famine appears to have causative factors to the larger occurrence of the vitamin deficiencies.  overall, the under-fives who were affected by severe drought were more susceptible to the deficiency of the micronutrients compared to those who were not affected by drought (Belesova et al., 2019). 

Vitamin A routine supplement to under-fives is recognized to reduce the dangers of death and illness such as HIV and AIDS infection, diarrheal diseases, measles and malaria. These might be probably as a result of the of vitamin A actions (Clohossey et al., 2014). These resistant functions of this vitamin have been defined in experimental trials which are related to therapeutic outcomes of supplement. These effects of illness such as measles are associated to improved antibody production as well as lymphocyte proliferation. And effect of reduction in severity in diarrheal illness might be attributed to the vitamin A outcome in supporting epithelia in the gut, while positive results in HIV-infected children might be effect of increase in T-cell lymphopoiesis. No definite outcome of vitamin A supplement effect on lymphocyte activation as well as cytokine production or. In some circumstances, the supplementation had possible advance effect to the infants antibody response to immunization such as tetanus, measles and polio. (Villamor & Fawzi, 2005a) the deficiency of the Vitamin A depresses resistance whereas vitamin A supplementation decreases diseases and death, mainly from measles and diarrhea. The supplement similarly reduces the death proportion in HIV/AIDS in infected children and interrupting HIV ailment. Zinc deficit is one of the interesting factors in tuberculosis, imposing the risk of vitamin A deficiency. Supplement with numerous nutrients (including zinc) rather than vitamin A unaccompanied with other micronutrient may be very important in patients suffering from tuberculosis, but clinical trials on such amalgamation are wanting (Mathur, 2007). 

Kaduna is among 47 Counties and situated in the Northern part of  Nigeria, with an area of 56,685.9 Km2. The county borders Somalia to the east, Ethiopia to the North and garissa to the south.The Nigeria 2019 Population and Housing census indicate that the county had a total population of 781,214. Comprising of 53% Males population whereas female population account for 47%. The infant and under-five death rates are at (44/1000). Malnutrition remains important public health subjects in Kaduna with prevalence of stunting and wasting at 26.4 and 14.2 percent respectively compared to national average of 26.0 and 4.1 percent, respectively as per demographic health survey 2014 according to government of Kaduna, 2018. 

It is clear that vitamin A is important in the development of children under the age of 5 years.  Available studies have focused on uptake of vitamin A supplementation. Studies on effect of vitamin A supplementation especially in arid and semi-arid area are however scarce. This study therefore seeks to determine prevalence of vitamin a deficiency among children under five years of age in Nigeria.