Study of Serum Vitamin D and Calcium Levels Among Under-5 Children in Ogun State and Their Association with Bone Health Indicators

Study of Serum Vitamin D and Calcium Levels Among Under-5 Children in Ogun State and Their Association with Bone Health Indicators

Abstract

Vitamin D and calcium are essential nutrients for bone development and overall growth in children. Deficiencies in these micronutrients are major contributors to poor skeletal formation and increased risk of rickets, especially in developing regions. This study examines serum vitamin D and calcium concentrations among under-five children in selected communities of Ogun State, Nigeria, and explores their association with bone health indicators.

Blood samples were collected from children attending primary health centers and analyzed using spectrophotometric methods for serum calcium and ELISA kits for vitamin D. Anthropometric data, including height, weight, and mid-arm circumference, were also recorded. The results were compared to established clinical reference ranges to identify deficiencies and correlations between serum biomarkers and bone health indicators.

Findings revealed that a significant proportion of the children exhibited low vitamin D and calcium levels, which were positively correlated with reduced height-for-age and other bone development parameters. The study emphasizes the urgent need for improved nutritional education, vitamin D supplementation, and outdoor sunlight exposure among children in Ogun State.

Keywords: Vitamin D, Calcium, Under-5 Children, Bone Health, Biochemical Assessment, Ogun State

CHAPTER ONE

1.0 Introduction

Bone health during early childhood is critical for long-term growth and physical development. Adequate levels of vitamin D and calcium are essential for the formation of strong bones and teeth. In Nigeria, particularly in Ogun State, under-five children often face nutritional deficiencies due to limited access to balanced diets and inadequate exposure to sunlight. Consequently, vitamin D deficiency has become a growing public health issue, leading to impaired bone mineralization and, in severe cases, rickets.

Vitamin D facilitates calcium absorption from the intestine and regulates calcium and phosphorus balance in the body. Without sufficient vitamin D, calcium absorption decreases, causing reduced bone density and poor skeletal structure. Calcium, on the other hand, serves as the building block for bone tissue. A deficiency in either nutrient disrupts normal bone metabolism and can result in developmental delays or deformities in children.

Therefore, assessing the biochemical status of vitamin D and calcium among under-five children is vital for understanding their bone health. This study aims to investigate the relationship between serum vitamin D and calcium levels and bone health indicators among children in Ogun State.

1.1 Background to the Study

Globally, vitamin D deficiency is one of the most common nutritional disorders, affecting both developing and developed nations. It arises mainly from inadequate sunlight exposure, low dietary intake, or malabsorption of nutrients. In sub-Saharan Africa, rapid urbanization and changing lifestyles have further reduced outdoor activities among children, thereby limiting their exposure to ultraviolet B (UVB) rays required for vitamin D synthesis in the skin.

In Ogun State, several rural and peri-urban communities rely on carbohydrate-based diets low in essential micronutrients. Consequently, calcium intake is often insufficient to meet the body’s developmental needs. Studies have shown that vitamin D deficiency not only weakens bones but also impairs immune function and muscle performance. The biochemical assessment of these nutrients provides valuable insights into the prevalence of hidden malnutrition and its effects on childhood growth patterns.

Regular monitoring of serum vitamin D and calcium can help identify at-risk populations and guide interventions aimed at preventing rickets and other bone-related disorders.

1.2 Statement of the Problem

Childhood rickets and poor bone development remain significant health challenges in many Nigerian communities. Despite the abundance of sunlight, cases of vitamin D deficiency are increasing due to indoor lifestyles, poor diet, and cultural practices that limit sun exposure. Furthermore, many parents are unaware of the importance of calcium-rich foods and vitamin D sources in early childhood nutrition. The absence of biochemical monitoring programs in primary healthcare centers further complicates early detection.

Therefore, this study addresses the lack of current biochemical data on vitamin D and calcium status among under-five children in Ogun State and examines how these nutrients correlate with measurable bone health indicators.

1.3 Aim and Objectives of the Study

Aim:
To determine serum vitamin D and calcium levels among under-five children in Ogun State and evaluate their association with bone health indicators.

Objectives:

1. To measure serum concentrations of vitamin D and calcium among under-five children in selected communities.

2. To assess the relationship between vitamin D, calcium levels, and bone health indicators such as height, weight, and bone tenderness.

3. To compare observed biochemical values with standard reference ranges for children.

4. To recommend nutritional and public health interventions to improve bone health outcomes.

1.4 Research Questions

1. What are the serum vitamin D and calcium levels among under-five children in Ogun State?

2. How do these biochemical values relate to bone health indicators such as height-for-age and body weight?

3. Are vitamin D and calcium deficiencies prevalent among children in rural and urban areas of Ogun State?

4. What interventions can improve vitamin D and calcium status among children in the state?

1.5 Significance of the Study

This study is important for public health and pediatric nutrition in Nigeria. It provides biochemical evidence of micronutrient deficiencies among children and their effects on bone health. The findings will help policymakers, healthcare providers, and nutritionists design effective strategies for supplementation, dietary improvement, and awareness campaigns. Additionally, the results will contribute to existing literature on childhood malnutrition and promote sustainable solutions for improving child health outcomes.

1.6 Scope of the Study

The research focuses on under-five children attending primary healthcare centers in selected local government areas of Ogun State. It assesses serum vitamin D and calcium levels and evaluates their associations with bone development indicators. Other nutritional biomarkers such as magnesium or phosphorus are beyond the scope of this study.

1.7 Definition of Terms

• Vitamin D: A fat-soluble vitamin that promotes calcium absorption and bone mineralization.

• Calcium: A mineral essential for the development of bones, teeth, and muscle function.

• Under-5 Children: Children aged below five years, a critical period for growth and development.

• Bone Health Indicators: Physiological parameters, such as height, weight, and bone tenderness, used to assess skeletal development.

• Rickets: A childhood bone disorder caused by prolonged vitamin D or calcium deficiency.