Background: According to WHO, Vitamin A is one of the essential micronutrient whose deficiency affects approximately one third of children under five years around the world. About 40,000 children die annually due to underweight and vitamin A deficiency in Kenya.  Nationally Vitamin A coverage is 40% with deficiency being ranked 7^th mortality risk factor (5^th in Busia) and an all spectrum prevalence of 61.8% in preschool children. Studies have recommended high-dose supplementation and zinc administration to deficient populations.

Objective: The main objective of this study is to determine the efficacy of a stepped up Vitamin A supplementation dose to infants (6-12 months) in Busia County in Kenya.

Materials and methods: Mixed methods design will address the efficacy of different doses of Vitamin A and challenges associated with it’s supplementation. Under quantitative, biochemical analysis sheets, check lists and mother child health records will be used to test the theory of improved immunity with a higher dose, which predicts that a stepped up Vitamin A dose (200,000 IU) as compared to standard dose (100,000 IU) will influence retinol levels and immuno-biomakers positively hence reduced morbidity episodes for 120 infants (6-12 months) at Busia Level 4 Hospital, Busia County.  Qualitative data using key informant interviews and focus group discussions will explore the challenges of Vitamin A supplementation for 72 mothers, 4 County Health Management Team (4) and 6 staff. The mixed methods design will bring together the strengths of both methods to triangulate and corroborate results. Quantitative and qualitative data will be analyzed using descriptive statistics and thematic framework respectively. The proposal will be submitted to Scientific and Ethical Review Unit at KEMRI for approval. The results will benefit the Ministry of Health with policy briefs, programme implementers with improved intervention strategies, scientists with new knowledge and mothers/infants with improved child survival outcomes.