Duong Ngoc Truong

Background/Objectives: Linear growth in children reflects cumulative influences of nutrition, health, and skeletal development. Vitamin K₂, particularly menaquinone-7 (MK-7), plays an important role in bone mineralization, yet evidence regarding its potential relationship with height growth in children remains limited. This study evaluated the association between continuous MK-7 supplementation and longitudinal height growth in children. Methods: A longitudinal observational study was conducted among 1150 apparently healthy children aged 6–14 years in Hanoi, Vietnam (2022–2025), including 613 controls and 537 children receiving MK-7 supplementation. MK-7 was administered orally at 360 µg/day from baseline throughout follow-up. A total of 3491 repeated height measurements were collected. Analyses were stratified according to pubertal stage (no-puberty and pre-puberty). Height gain was summarized according to follow-up duration, and initial mixed-effects models were used to explore longitudinal growth trajectories. Because substantial follow-up imbalance was observed after the first follow-up assessment, the primary regression analyses were subsequently restricted to baseline and first follow-up observations. Multivariable linear regression models evaluated the interaction between MK-7 supplementation and follow-up duration after adjustment for age, sex, baseline body mass index-for-age Z-score, early sleep, and physical activity. Results: Height gain increased significantly with follow-up duration across all analyses (β range: 0.49–0.58 cm/month; all p < 0.001). MK-7 supplementation alone was not independently associated with height gain; however, positive interactions between MK-7 supplementation and follow-up duration were observed in several subgroup analyses. In the overall cohort, the interaction estimate was β = 0.05 cm/month (95% CI: 0.02–0.09). Positive interactions were observed in no-puberty children (β = 0.05; 95% CI: 0.01–0.09) and pre-puberty children (β = 0.06; 95% CI: 0.03–0.09). The largest interaction estimate was observed among pre-puberty boys (β = 0.10; 95% CI: 0.07–0.13), whereas no statistically significant interaction was observed among girls in the pre-puberty subgroup. Conclusions: The findings suggest that continuous MK-7 supplementation may be associated with progressively greater height gain over time rather than an immediate increase in height. The observed associations appeared more evident with longer follow-up duration, particularly among pre-pubertal boys. However, given the observational design and substantial follow-up imbalance between groups, the findings should be interpreted cautiously. Further prospective studies with balanced longitudinal follow-up are needed to clarify the potential relationship between MK-7 supplementation and pediatric linear growth.

Objective: To assess the prevalence and associated factors of malnutrition—including stunting, thinness, overweight, and obesity—among Vietnamese children aged 6–17 years, and to identify demographic, geographic, and behavioral correlates to inform targeted nutrition interventions. Methods: A cross-sectional, nationally representative study was conducted from January 2024 to June 2025 using data from the MIDU Assessment Program. A multistage stratified random sampling approach recruited 43,505 children aged 6–17 years across all regions of Vietnam. Anthropometric measurements were obtained following WHO 2007 growth reference standards. Stunting was defined as height-for-age Z-score (HAZ) < −2 SD, and overweight/obesity as body mass index-for-age Z-score (BAZ) > +1 SD. Data on demographic characteristics, sleep patterns, sports participation, vitamin K₂ use, and pubertal status were collected via structured questionnaires. Multivariable logistic regression was used to identify factors associated with stunting and overweight/obesity. Results: Overall, 3.9% were stunted, 5.1% were thin, 20.7% were overweight, and 11.4% were obese; 8.6% had any undernutrition and 39.5% had any form of malnutrition. Stunting was significantly associated with being male (OR = 1.37, 95% CI: 1.24–1.52), older age—particularly 14–17 years (OR = 6.56, 95% CI: 5.48–7.84)—and residing in the Northern midlands, North Central, South Central, and Central Highlands regions. In contrast, frequent sports participation (OR = 0.76, 95% CI: 0.68–0.84), daily vitamin K₂–MK₇ use (OR = 0.82, 95% CI: 0.72–0.93), and having reached puberty (OR = 0.26, 95% CI: 0.22–0.30) were associated with lower odds of stunting. For overweight and obesity, lower odds were found among females (OR = 0.48, 95% CI: 0.46–0.51) and older children, while higher odds occurred among those living in the Southeast (OR = 1.45, 95% CI: 1.36–1.53) and Mekong River Delta (OR = 1.35, 95% CI: 1.24–1.48) regions. Early sleep (OR = 0.91, 95% CI: 0.87–0.95) and sports participation (OR = 1.07, 95% CI: 1.02–1.11) showed modest associations, whereas vitamin K₂ use and puberty were not significant predictors. Conclusions: Vietnamese school-aged children face a significant rate of malnutrition, with regional, gender, and age disparities.