Vitamins and immune defense in children: evidence and practical guidance

The role of vitamins in pediatric immune system development

During childhood, the immune system undergoes progressive maturation and is physiologically more exposed to environmental challenges—particularly during seasonal transitions and in high-socialization settings such as daycare and school.

Recurrent colds and upper respiratory tract infections are common in early life. While these episodes are part of normal immune adaptation, it is now well established that adequate nutritional status plays a key role in supporting proper immune function, helping to ensure an effective and well-regulated immune response.

Major pediatric scientific societies emphasize the importance of a healthy lifestyle and a balanced diet capable of providing an appropriate intake of essential micronutrients. Within this framework, vitamins play a central role in immune defense mechanisms and growth-related processes.

Vitamins and the immune system: a delicate balance during growth

Vitamins and minerals actively participate in numerous physiological processes involved in pediatric development, including those related to immune system function. Adequate intake of these micronutrients contributes to:

• maintenance of physical and immunological barriers
• production and function of immune cells
• regulation of inflammatory and immune responses

A varied and balanced diet, rich in fruits, vegetables, and high-quality foods, remains the primary strategy for supporting immune defenses in children. Understanding which vitamins are most involved in immune mechanisms helps clarify the importance of nutritional balance throughout different stages of growth.

Key vitamins involved in pediatric immune function

Vitamin A

Vitamin A contributes to the integrity of mucosal surfaces and skin, which represent the body’s first line of defense against external pathogens. It also plays a role in modulating immune responses.

Dietary sources include orange-colored foods such as carrots, pumpkin, apricots, and melon, as well as leafy green vegetables, liver, and dairy products.

B-Complex Vitamins (B2, B6, B12)

B vitamins are essential for metabolic processes and proper cellular function. Specifically:

• Vitamin B2 (riboflavin) supports energy metabolism and has antioxidant properties
• Vitamin B6 (pyridoxine) is involved in cytokine and antibody synthesis
• Vitamin B12 (cobalamin) is essential for red blood cell formation and normal immune system function

These vitamins are primarily found in milk and dairy products, eggs, meat, fish, whole grains, legumes, and leafy green vegetables.

Vitamin C (Ascorbic Acid)

Known for its antioxidant activity, vitamin C helps protect cells from oxidative stress and supports normal immune function, particularly during periods of increased exposure to environmental stressors.

Food sources include citrus fruits, kiwi, bell peppers, tomatoes, and leafy green vegetables.

Vitamin D

In addition to its well-established role in calcium metabolism and bone health, vitamin D is involved in regulating immune responses. Endogenous synthesis occurs mainly through exposure to sunlight, while smaller amounts are obtained from dietary sources such as fatty fish, eggs, and leafy green vegetables.

To further explore the role of essential micronutrients during growth, see our in-depth content on vitamins and minerals in pediatric age.

Daily habits that support immune health in children

Alongside a balanced diet, several everyday practices contribute to proper immune system function:

• proper hand hygiene to limit the spread of microorganisms
• regular ventilation of indoor environments
• outdoor physical activity, even during colder months when weather conditions allow
• adequate sleep, which is essential for recovery and physiological regulation
• basic respiratory hygiene practices, particularly in school settings

Vitamin deficiencies in childhood: when to pay attention

At certain stages of growth, insufficient vitamin intake may be associated with increased susceptibility to infections and slower recovery. In such cases, diet alone may not fully meet nutritional requirements.

A careful evaluation by a pediatrician or qualified healthcare professional is essential to identify potential deficiencies and, when appropriate, to define a targeted nutritional strategy—always tailored to the individual child’s needs.

This content is intended for informational purposes only and does not replace medical advice. For personalized assessments of a child’s health, consultation with a pediatrician or healthcare professional is always recommended.