Vitamins are essential micronutrients indispensable for sustaining human health (1). They are classified into water-soluble vitamins (including vitamin C and B-complex vitamins) and fat-soluble vitamins (such as vitamins A, D, E, and K). These nutrients are integral to numerous physiological processes, including energy metabolism, antioxidant defense, immune modulation, and blood coagulation. Vitamin deficiencies can precipitate a range of adverse health outcomes, including compromised immune function, skeletal abnormalities, and cognitive impairments (2–6).

Childhood vitamin insufficiencies/deficiencies represent a significant global public health concern. Current evidence indicates that approximately 25% of children worldwide experience subclinical vitamin A (VA) deficiency, with nearly 250 million children annually at risk of blindness due to inadequate VA intake (7). In China, the prevalence of pediatric vitamin deficiencies, particularly VA and vitamin D (VD), has shown a rising trend. A cross-sectional survey conducted in Jiangsu Province between 2016 and 2017 reported a 0.8% prevalence of VA deficiency among children, with an additional 15.8% classified as marginally deficient (8). Notably, geographic disparities persist, with rural children displaying a significantly elevated risk of VA deficiency compared to their urban counterparts (9). VD deficiency is similarly concerning, affecting 23.2% of children with deficient levels and 54.2% with insufficient levels. The pediatric VD status is influenced by a range of factors, including sex, age, geographical location, duration of sunlight exposure, and maternal education (10). In northern China, children exhibit increased rates of VD deficiency during winter due to reduced ultraviolet radiation exposure (9). Moreover, deficiencies in B vitamins among children constitute a substantial global public health challenge (11). As children age, their physiological demand for B vitamins increases; however, dietary practices in many households fail to meet these requirements, resulting in significant nutritional gaps (12).

Currently, evidence suggests an age-dependent increase in the prevalence of vitamin deficiencies among children (13). Children’s nutritional status directly impacts their future health and developmental potential. However, comprehensive investigations into the vitamin nutritional levels and status of children in Henan, China are still lacking. This study aims to systematically assess the nutritional status of various vitamins among children in Henan, China and identify key influencing factors through epidemiological surveys. The outcomes are intended to inform public health policy, support clinicians in identifying high-risk groups, and guide the development of targeted intervention strategies. Additionally, the findings will provide practical insights into pediatric healthcare and nutrition, promoting a more evidence-based and standardized approach to managing child health.

Vitamins are fundamental nutrients essential for maintaining normal physiological functions, particularly during key stages of growth and development in childhood. Adequate vitamin intake is crucial for both physical and cognitive maturation. Vitamin deficiencies in children constitute a major global public health issue, exacerbated by the rapid progression of globalization and urbanization, particularly in low- and middle-income countries. Insufficient vitamin intake during childhood is associated with stunted growth, compromised immunity, and impaired cognitive abilities. Deficiencies in VA are linked to a range of visual impairments, including night blindness, xerophthalmia, and severe complications such as corneal ulceration and potential blindness (15). According to the World Health Organization, approximately 200 million children worldwide experience VA deficiency, directly affecting growth and immune function (16). VD deficiency is associated with skeletal abnormalities, including rickets (17), and recent studies have identified correlations between VD deficiency and increased risks of infectious diseases, cardiovascular conditions, and neurological disorders (5, 18, 19). Additionally, VE deficiency is linked to neurological impairments and immune dysfunction (20), while B vitamin deficiencies are implicated in various cardiovascular, neurological, and dermatological conditions (21–24).

Henan Province, situated in Henan, China, is the cradle of Huaxia civilization with over 3,200 years of recorded history. It served as the cultural, economic, and political center of China until approximately 1,000 years ago. Henan has a substantial child population; according to data from the Henan Provincial Government at the end of 2024, children under 15 years old numbered 20.71 million, constituting 21.2% of the total population. Furthermore, Henan Provincial Children’s Hospital, as the sole National Regional Medical Center for Children in Henan, China, provides services to children from Henan and neighboring provinces. However, the prevalence of vitamin deficiency disorders among children is increasing, and children’s nutritional status directly impacts their future health and developmental potential. Therefore, it is imperative to investigate the vitamin nutritional levels and status of children in Henan, China.

This study provides the first comprehensive assessment of multiple vitamin levels and nutritional status among children in Henan, China. It found that female children exhibited a higher prevalence of VD insufficiency. This disparity may be attributed to reduced sunlight exposure, thereby limiting endogenous VD synthesis. In contrast, female children typically present with higher levels of VE, VB2, VB5, and VC, accompanied by lower insufficiency rates compared to males. Sex-specific variations in vitamin requirements are evident; adolescent males generally exhibit higher energy and vitamin demands, which are attributed to accelerated growth rates, increased weight gain, and higher physical activity levels. Moreover, dietary patterns differ between sex, with females tending to adopt more balanced nutritional practices. In contrast, males are more likely to engage in selective eating, increasing the risk of micronutrient deficiencies.

Vitamin requirements also vary significantly across developmental stages. Infants necessitate increased VD intake to support proper skeletal growth, while adolescents require higher levels of VA and VC to facilitate immune system maturation (25). Changes in dietary habits, nutrient consumption, and physiological demands with age can result in vitamin deficiencies, adversely affecting health outcomes (26). The analysis identified distinct age-related trends, with levels of VD, VE, VB1, VB2, VB3, VB5, VB7, and VC progressively declining as age increases. Correspondingly, insufficiency rates for VD, VE, VB1, VB7, and VC rise with age, reaching their lowest levels in infants under 2 years and peaking in adolescent age over 12 years. This pattern likely reflects optimal nutrition during infancy, characterized by breastfeeding, fortified formulas, and routine VD supplementation to prevent rickets, contrasted with decreased dietary regulation and reduced outdoor activities as children grow older.

Seasonal fluctuations in vitamin levels arise from a complex interplay of factors, including sunlight exposure, dietary patterns, and physiological adaptations. VD levels exhibit pronounced seasonal variability, with deficiency risk significantly increasing during winter due to reduced daylight and lower UVB radiation (27). This study corroborates these findings, identifying the lowest VD levels and the highest insufficiency rates during winter. Seasonal variations also significantly affect VA, VE, VB1, VB3, VB5, VB7, and VC levels. Data analysis reveals that insufficiency rates for VA and VC peak during summer, while VE insufficiency is most prevalent in spring, and VC insufficiency rates increase in summer. These seasonal differences are likely influenced by the variable availability of fresh fruits and vegetables throughout the year (28).

This comprehensive analysis identifies significant associations between vitamin insufficiency rates and factors such as sex, age, and seasonal variations. However, several limitations should be considered. First, the single-center design may restrict the generalizability of our findings, and future multicenter studies are warranted for validation. Second, the lack of data on dietary habits, lifestyle factors, and socioeconomic status may introduce residual confounding. Furthermore, the limited sample size in certain subgroups—particularly within the broadly defined 12-18-year age group encompassing diverse pubertal stages—restricted finer age stratification and may have obscured more nuanced developmental trends. Additionally, the assessment of thiamine status relied solely on total blood thiamine levels rather than more sensitive functional assays, which may reduce the sensitivity to detect functional thiamine insufficiency.

In conclusion, this study reveals a high prevalence of vitamin insufficiencies, particularly vitamins B7, D, A, and C among children in Henan, China, with variations significantly associated with sex, age, and season. These findings provide critical evidence to guide public health policy formulation and support the implementation of targeted nutritional interventions, such as age-specific supplementation and seasonal dietary recommendations, to improve pediatric health outcomes in this population.