Hypovitaminosis D and Mild Hypocalcaemia Are Highly Prevalent among Young Vietnamese Children and Women and Related to Low Dietary Intake

Abstract

IntroductionIn many developing countries including Vietnam, data are lacking on vitamin D and calcium deficiencies whereas those deficiencies can play an important role in the development of bone health and possibly non-communicable diseases. The purpose of this study was to determine the overall prevalence of vitamin D and calcium deficiencies in women and young children and their nutritional related risk factors.MethodsA cross-sectional study conducted among 595 women of reproductive age and 532 children <5 years from 19 provinces of Vietnam. For each individual, data concerning daily diet, socioeconomic group, anthropometric status were obtained, and plasma concentrations of calcium and vitamin D were measured.ResultsThe prevalence of hypovitaminosis D status was very high, with the prevalence of vitamin D deficiency (25(OH)D<30 nmol/L) and insufficiency (25(OH)D between 30–49.9 nmol/L) being 17% and 40% in women and 21% and 37% in children, respectively. Using more liberal cut-off of 75 nmol/L, approximately 90% of the women and children were classified as having hypovitaminosis D. Overweight/obese women had a 2 times lower risk (OR = 0.46, [0.24–0.90]) for vitamin D deficiency than non-overweight and non-obese women. No participant had severe calcium deficiency but moderate and mild hypocalcaemia (plasma calcium concentrations between 1.15-0.9 mmol/L for mild deficiency and between 0.9-0.8 mmol/L for moderate deficiency) affected respectively 14% and 83% of the women with 97% of the children having mild hypocalcaemia. Women and children consumed about 1% of the Institute of Medicine (IOM) recommended nutrient intake (RNI) for vitamin D and less than 43% of the RNI for calcium.ConclusionOur study suggests that calcium and vitamin D deficiencies represent a major public health concern in Vietnam. Thus, actions to improve the vitamin D and calcium status of the Vietnamese population should be considered.

Effect of Vitamin D supplementation to reduce respiratory infections in children and adolescents in Vietnam: A randomized controlled trial

“…Only 17% of participants in our study had vitamin D levels <50 nmol/L, in contrast to a previous study from Vietnam where >50% children had insufficiency or deficiency . The relatively high vitamin D levels in our study may have reduced the effectiveness of vitamin D supplementation in preventing influenza.…”

“…The attack rate for all respiratory viruses in our study was 35%, which is comparable to other studies that have used RT‐PCR to detect infection in children . A study in the same population in Vietnam reported similar attack rates as ours . Also, detection of the types of viruses and their relative frequency was similar to previous reports.…”

“…Conducting randomized controlled trials of vitamin D supplementation to prevent influenza and other respiratory infections can be challenging in settings where vitamin D deficiency may not be prevalent and uptake of influenza vaccination is relatively high . In contrast, in most low‐ and middle‐income countries, such as Vietnam, children are not routinely vaccinated against influenza and vitamin D deficiency in children has been reported to be more prevalent …”

“…21,22 In contrast, in most low-and middle-income countries, such as Vietnam, children are not routinely vaccinated against influenza and vitamin D deficiency in children has been reported to be more prevalent. 23 We conducted a randomized trial of vitamin D in children in Vietnam to assess its effectiveness in reducing laboratory-confirmed influenza and non-influenza viral respiratory tract infections. We hypothesized that vitamin D would reduce both laboratory-confirmed influenza and non-influenza respiratory viral infection compared to placebo.…”

Predictive Value of Ionized Calcium in Critically Ill Patients: An Analysis of a Large Clinical Database MIMIC II

“…The knots were chosen according to conventional classification of iCa ranges: relative to the normal range of 1.15–1.25 mmol/L, we defined hypocalcemia as mild, moderate and severe as 0.9–1.15, 0.8–0.9 and <0.8 mmol/L, respectively. Hypercalcemia was divided into mild, moderate and severe as 1.25–1.35, 1.35–1.45 and >1.45 mmol/L, respectively [11], [12]. Potential multicollinearity between covariates in the model were quantified by using variance inflation factor (VIF) which provided an index that measures how much the variance of an estimated regression coefficient is increased because of collinearity [13].…”