Vitamin D Maintains Growth and Bone Mineral Density against a Background of Severe Vitamin A Deficiency and Moderate Toxicity in a Swine Model.

Excessive vitamin A (VA) negatively impacts bone. Interactions between VA and vitamin D (VD) in bone health are not well-understood. This study used a traditional two-by-two factorial design.

Repeated High-Dose Vitamin A Supplements, Standard of Care for Treating Xerophthalmia, Leads to Hypervitaminosis A in Piglets.

Background: Vitamin A (VA) deficiency and excess negatively affect development, growth, and bone health. The World Health Organization's standard of care for xerophthalmia due to VA deficiency, is 3 high-dose VA supplements of 50,000-200,000 IU, based on age, which may cause hypervitaminosis A in some individuals.

Objectives: This study measured VA status following 3 VA doses in 2 piglet studies.

A Correlation Study of Plasma and Breast Milk Retinol Concentrations in Breastfeeding Women in China.

Retinol in breast milk is related to plasma concentration among breastfeeding women, but the linear or curvilinear relationships between the two remains unclear. We conducted a cross-sectional study in 403 Chinese breastfeeding women at 42 ± 7 days postpartum. Plasma and breast milk samples were assayed using high performance liquid chromatography to determine the concentration of retinol.

A comparative study on indicators of vitamin A status and risk factors for sensitivity and specificity of the methods to detect vitamin A deficiency.

Background: Serum retinol (SR) and retinol-binding protein (RBP) are commonly used indicators, but they are affected by infections and inflammation. This study aimed to assess the sensitivity and specificity of VA indicators to detect vitamin A deficiency (VAD) in 36-59-month-old children living in a rural area in Burkina Faso.

Methods: In a community-based study, two cross-sectional surveys were carried out from November 2016 to September 2017 in the health district of Dandé in Burkina Faso.

Hepatic Vitamin A Concentrations and Association with Infectious Causes of Child Death.

Objectives: To assess postmortem vitamin A (VA) concentrations in children under 5 years of age and evaluate the association between VA deficiency (VAD) and infectious causes of death (CoD).

Study Design: In this cross-sectional study from the Child Health and Mortality Prevention Surveillance (CHAMPS) Network, liver biopsies collected within 72 hours of death were analyzed from 405 stillbirths and children under 5 years in Kenya and South Africa. Total liver VA (TLVA) concentrations were quantified using ultra-performance liquid chromatography, and cutoffs of ≤0.

Dietary intake of preformed vitamin A and provitamin A carotenoids are not associated with serum retinol and carotenoid concentrations among children 36-59 months of age in rural Burkina Faso: a cross-sectional study.

Purpose: This study aimed to assess the association between dietary intake of preformed vitamin A (VA) and pro-VA carotenoids and serum retinol and carotenoid concentrations among 36-59-month-old children in a rural area in Burkina Faso.

Methods: Two community-based cross-sectional studies were conducted in a rural area of Burkina Faso and included 115 children aged 36-59 months. Dietary intake of preformed VA and pro-VA was assessed directly by 24-h dietary recall.

Inadequate Niacin Intake Disrupts Growth and Retinol Homeostasis Resulting in Higher Liver and Lower Serum Retinol Concentrations in Male Rats.

Background: Niacin-derived nicotinamide adenine dinucleotide is an essential cofactor for many dehydrogenase enzymes involved in vitamin A (VA) metabolism. Several countries with high prevalence of VA deficiency rely on maize, a poor source of available niacin, as a dietary staple.

Objectives: This study evaluated the interaction of dietary niacin on VA homeostasis using male Sprague-Dawley rats, aged 21 d (baseline body weight 88.

Urinary 2- to 16α-hydroxyestrone ratio did not change with cruciferous vegetable intake in premenopausal women.

The mass ratio of urinary 2-hydroxyestrone to 16-α-hydroxyestrone (2:16) is hypothesized as a biomarker of breast cancer risk in premenopausal women, with higher ratios being theoretically protective. Cruciferous vegetable intake has been associated with higher urinary 2:16 in some studies. We investigated whether a whole-food supplement made from dried Brussels sprouts and kale would increase urinary 2:16 in comparison with placebo or cruciferous vegetables in women.

Association between Biomarkers of Inflammation and Total Liver Vitamin A Reserves Estimated by C-Retinol Isotope Dilution among Preschool Children in 5 African Countries.

Background: Vitamin A (VA) assessment is important for targeting public health programs. Retinol isotope dilution (RID) is a sensitive method to estimate total body VA stores (TBSs) and total liver reserves (TLRs), but the impact of subclinical inflammation on RID is unclear.

Objective: We determined the association between TBSs and TLRs, estimated by RID, and inflammation among preschool children without clinical infection in Burkina Faso, Cameroon, Ethiopia, South Africa, and Tanzania.

Anthocyanin and Lycopene Contents Do Not Affect β-Carotene Bioefficacy from Multicolored Carrots (Daucus carota L.) in Male Mongolian Gerbils.

Background: Anthocyanins and carotenoids are phytochemicals that may benefit health through provitamin A carotenoid (PAC), antioxidant, and anti-inflammatory activities. These bioactives may mitigate chronic diseases. Consumption of multiple phytochemicals may impact bioactivity in synergistic or antagonistic manners.

Comparison of Total Body Vitamin A Stores Using Individual versus Population C-Natural Abundance of Serum Retinol in Preschool Children and Women Residing in 6 Diverse African Countries.

Background: Stable isotope techniques using C to assess vitamin A (VA) dietary sources, absorption, and total body VA stores (TBSs) require determination of baseline C abundance. C-natural abundance is approximately 1.1% total carbon, but varies with foods consumed, supplements taken, and food fortification with synthetic retinyl palmitate.

Total Liver Vitamin A Reserves, Determined With 13C2-Retinol Isotope Dilution, are Similar Among Tanzanian Preschool Children in Areas With Low and High Vitamin A Exposure.

Background: In Tanzania, some districts have single vitamin A (VA) interventions and others have multiple interventions. There is limited information on total liver VA reserves (TLRs) among preschool children (PSC) in Tanzania.

Objectives: We assessed total body VA stores (TBSs) and TLRs among PSC living in 2 districts with low and high exposures to VA interventions using 13C-retinol isotope dilution.

Breast Milk Retinol Concentrations Reflect Total Liver Vitamin A Reserves and Dietary Exposure in Thai Lactating Women from Urban and Rural Areas.

Background: Measuring vitamin A (VA) status during lactation is required to inform dietary recommendations. Limited data exist on VA stores in women.

Objectives: Our objective was to assess VA status in lactating Thai women by measuring total body VA stores (TBSs), serum and breast milk retinol concentrations, and dietary intake.

Time Since Dose and Dietary Vitamin A Intake Affect Tracer Mixing in the 13C-Retinol Isotope Dilution Test in Male Rats.

Background: Retinol isotope dilution (RID) estimates total liver vitamin A reserves (TLRs), the gold-standard vitamin A (VA) biomarker. RID equation assumptions are based on limited data.

Objectives: We measured the impact of tracer choice, mixing period, and VA intake on tracer mixing [ratio of tracer enrichment in serum to that in liver stores (S)] in VA-deficient, -adequate, and hypervitaminotic rats.

Chronic and acute hypervitaminosis A are associated with suboptimal anthropometric measurements in a cohort of South African preschool children.

Background: Excessive vitamin A (VA) can cause bone resorption and impair growth. Government-mandated VA supplementation (VAS) and adequate intake through dietary fortification and liver consumption led to excessive VA in South African children.

Objectives: We evaluated the relation between VAS and underlying hypervitaminosis A assessed by retinol isotope dilution (RID) with measures of growth and bone turnover in this cohort.

Geographic and socio-demographic determinants of plasma retinol concentrations in Chinese pregnant and lactating women.

Purpose: To examine plasma retinol status and its determinants in Chinese pregnant or lactating women.

Methods: A cross-sectional study involving 1211 healthy women in mid-pregnancy, late pregnancy, or lactation was conducted in northern, central, and southern China. Plasma retinol concentration was determined by high-performance liquid chromatography.

Inflammation Adjustments to Serum Retinol and Retinol-Binding Protein Improve Specificity but Reduce Sensitivity when Estimating Vitamin A Deficiency Compared with the Modified Relative Dose-Response Test in Ghanaian Children.

Background: Serum retinol and retinol-binding protein (RBP) concentrations are commonly used biomarkers of vitamin A deficiency (VAD); however, evidence indicates that they are not always accurate, especially in populations with high exposure to inflammation.

Objective: The aim was to assess sensitivity and specificity of serum retinol and RBP concentrations to predict VAD, with and without adjustment for inflammation (using categorical and regression-adjusted approaches), using the modified relative dose-response (MRDR) as the reference standard for liver reserves.

Methods: This secondary analysis of diagnostic accuracy used inflammation and RBP data and analyzed serum retinol and MRDR from a subsample of women of reproductive age ( = 178) and preschool children ( = 166) in the cross-sectional 2017 Ghana Micronutrient Survey.

Biological evidence to define a vitamin A deficiency cutoff using total liver vitamin A reserves.

Vitamin A is a fat-soluble vitamin involved in essential functions including growth, immunity, reproduction, and vision. The vitamin A Dietary Reference Intakes (DRIs) for North Americans suggested that a minimally acceptable total liver vitamin A reserve (TLR) is 0.07 µmol/g, which is not explicitly expressed as a vitamin A deficiency cutoff.

Vitamin A deficiency has declined in Malawi, but with evidence of elevated vitamin A in children.

Background: Reduction of vitamin A deficiency (VAD) in Malawi coincided with introduction of vitamin A-fortified staple foods, alongside continued biannual high-dose vitamin A supplementation (VAS).

Objective: We describe coverage of vitamin A interventions and vitamin A status in the 2015-2016 Malawi Micronutrient Survey.

Methods: Food samples and biospecimens were collected within a representative household survey across 105 clusters.

Vitamin A-fortified rice increases total body vitamin A stores in lactating Thai women measured by retinol isotope dilution: a double-blind, randomized, controlled trial.

Background: Lactating women are at increased risk for vitamin A (VA) deficiency due to demands for breast milk content and limited hepatic stores for women in some countries. Previously, consumption of triple-fortified rice, which included VA, iron, and zinc, successfully improved the VA status of Thai children in whom their total body VA stores (TBSs) were doubled in 2 mo.

Objective: This study assessed the efficacy of consuming VA-fortified rice, which delivered 500 µg retinol activity equivalents (RAEs)/d, on TBSs and estimated total liver VA reserves (TLRs) in Thai lactating women using the retinol isotope dilution (RID) test.

Relation between Timing of High-Dose Vitamin A Supplementation and Modified-Relative-Dose-Response Values in Children 12-23 Months in Uganda.

Background: High-dose vitamin A (VA) supplements (VAS) can temporarily affect VA status. Hence, micronutrient surveys might need to be timed around VAS campaigns to accurately estimate VA deficiency (VAD) prevalence. Little is known about optimal timing of micronutrient surveys when the modified-relative-dose-response (MRDR) is used as a VA indicator.

Adequate vitamin A liver stores estimated by the modified relative dose response test are positively associated with breastfeeding but not vitamin A supplementation in Senegalese urban children 9-23 months old: A comparative cross-sectional study.

Vitamin A supplementation (VAS) in 6-59-month-old children is recommended but its sustainability is currently questioned. In Senegal, available data suggest that VAS should be maintained, but geographic and age-related specificities need to be addressed to better implement and target VAS programming. The objective of this comparative cross-sectional study, conducted in urban settings of Dakar, was to compare the vitamin A liver stores (VALS) assessed using the modified-relative dose response (MRDR) test between supplemented and non-supplemented 9-23 month-old children and to study their relationship with VAS.