Changes in Vitamin A Levels and the Effect of Early Vitamin A Supplementation on Vitamin A Levels in Infants Throughout the First 6 Months of Life: A Prospective Cohort Study in Chongqing, China

Abstract

Objectives: This study aimed to explore the changes in infant vitamin A (VA) status and the effect of early VA supplementation on VA level throughout the first 6 months of life.Methods: A prospective cohort study was conducted in Chongqing, China. A total of 1,016 healthy infants were enrolled at birth. Then, 930, 882, 854 and 822 healthy infants were followed up at postnatal day 7 and postnatal months 1, 3, and 6, respectively. Blood samples and dietary survey and physical development data were collected. Serum VA was measured by chromatography tandem-mass spectrometry and was classified according to the VA deficiency (VAD) criteria for older children aged 6–70 months (<0.70, 0.70–1.05, ≥1.05 μmol/L). Normally distributed continuous variables are presented as the mean ± standard deviation. The categorical variables are described by the frequency and percentage (%). The reference interval for the VA level was the 2.5th−97.5th percentile. Changes in VA status with age and the relationship of VA supplementation with VA level were investigated by generalized estimating equations followed by Bonferroni post hoc test, controlling for the effects of feeding pattern and sex.Results: Infant VA levels increased significantly from 0.499 ± 0.146 to 1.061 ± 0.414 μmol/L with age at 6 months, even without VA supplementation (P < 0.05). From birth to 6 months, the percentage of infants with a VA level <0.70 μmol/L decreased from 88.6 to 19.5%. During follow-up, no infant demonstrated clinical VAD conditions, such as night blindness, conjunctival xerosis or Bitot's spots. Less than 7.0% of infants were underdeveloped in terms of weight, length and head circumference. The VA status of infants with VA≥0.588 μmol/L at birth gradually increased to adequate VA (VA ≥ 1.05 μmol/L) at 6 months. For these infants, there was no significant difference in VA level between the VA supplementation and non-supplementation groups (P > 0.05). Infants with VA <0.430 μmol/L at birth still had VA <0.70 μmol/L at 6 months; in this group, VA levels increased by 0.08 μmol/L more among supplemented infants than among non-supplemented infants (P < 0.05).Conclusions: A low VA level among neonates at birth may be a normal physiological state and may increase with age; thus, not all neonates may need early VA supplementation. More multicenter studies are needed to determine a new cutoff point for the diagnosis of neonatal VAD and the administration of nutritional intervention.

Burden of Nutritional Deficiencies in China: Findings from the Global Burden of Disease Study 2019

“…The number of children with a marginal vitamin A deficiency had also increased [ 18 ]. In the future, efforts should be made to improve the monitoring of the vitamin A status of key populations, and to clarify the critical points of clinical diagnosis and nutritional intervention for vitamin A deficiency in different age groups, especially infants and young children [ 19 , 20 ].…”

Correlation analysis between vitamin A, D, and E status with altitude, seasonal variation, and other factors, among children aged 0–6 years in a Chinese population living in the Tibetan plateau of Ganzi prefecture

“…Possible explanations for this include: The low Vit A and D levels of neonates at birth may be a normal physiological state that increases with age. 34 Infant Vit A, and D, is mainly derived from the mother and mother's milk, 35 whereas Tibetan mothers during pregnancy are given a traditional diet, which is low in Vit A, and D, 36 such as barley, wheat, potatoes, beef and mutton, yogurt, and butter. During late pregnancy reserves of Vit A, and D are low; therefore, their concentrations in the mother's milk are insufficient to satisfy the needs of the developing fetus, especially normal physiological function and bone formation and they rarely receive foods rich in these vitamins, such as cod liver oil.…”

“…With age, the body's demand for Vit E increases, and an unbalanced diet cannot provide sufficient vitamins, resulting in a relatively high level of deficiency. 34 …”

“…This may be associated with breast feeding in infancy, where the Vit E content is higher. With age, the body's demand for Vit E increases, and an unbalanced diet cannot provide sufficient vitamins, resulting in a relatively high level of deficiency 34 …”

Vitamin A Levels Among Pre-School Children of Central and Western China

“…However, in impoverished national counties, the prevalence of VAD among children was up to 3.99%, and the prevalence of VAI was found to have increased to 52.71%, evidencing the current poor nutritional status of vitamin A among children in impoverished counties of China. We believe that different groups of people should consider giving different vitamin A supplementation strategies ( 27 ). Policies, related sources and guidelines are an urgent pre-requisite to ensure the improvement of vitamin A nutrition in impoverished counties.…”