Associations of Maternal Vitamin B12 Concentration in Pregnancy With the Risks of Preterm Birth and Low Birth Weight: A Systematic Review and Meta-Analysis of Individual Participant Data.

Vitamin B12 (hereafter referred to as B12) deficiency in pregnancy is prevalent and has been associated with both lower birth weight (birth weight <2,500 g) and preterm birth (length of gestation <37 weeks). Nevertheless, current evidence is contradictory. We performed a systematic review and a meta-analysis of individual participant data to evaluate the associations of maternal serum or plasma B12 concentrations in pregnancy with offspring birth weight and length of gestation.

Folate and cobalamin status in relation to diet in healthy 2-y-old children.

Background: Limited data exist on sources of folate and cobalamin in the toddler diet.

Objective: We examined the influence of diet on folate and cobalamin status in healthy toddlers in an unfortified population.

Design: Dietary intake was assessed in 178 children, aged 24 mo, by using 7-d food records and related to serum folate and cobalamin status in 155 children.

Maternal folate and cobalamin status predicts vitamin status in newborns and 6-month-old infants.

Our aim in this longitudinal study was to determine predictors of folate and cobalamin status in infancy. Data were collected from 364 mother-infant pairs with blood measurements from pregnancy ( approximately 18 wk; n = 149), newborns (cord serum; n = 361), and 6-mo-old partially or exclusively breast-fed children (n = 221). Serum/plasma folate, cobalamin, holotranscobalamin (holoTC), holohaptocorrin (holoHC), methylmalonic acid (MMA) and total homocysteine (tHcy) at birth and 6 mo were related to maternal vitamin status, parity, lifestyle variables, and anthropometry.

Folate and cobalamin status in relation to breastfeeding and weaning in healthy infants.

Background: Folate and cobalamin status changes markedly during infancy.

Objective: We aimed to examine the influence of breastfeeding on folate and cobalamin status in healthy infants.

Design: In a longitudinal study, we measured serum folate, cobalamin, holotranscobalamin, holohaptocorrin, methylmalonic acid, and homocysteine at birth and at ages 6, 12, and 24 mo (n = 361, 262, 244, and 224, respectively).

Predictors of serum ferritin and serum soluble transferrin receptor in newborns and their associations with iron status during the first 2 y of life.

Background: Adequate iron status at birth may prevent iron deficiency in early childhood.

Objectives: We aimed to identify predictors of serum ferritin (SF) and serum soluble transferrin receptor (sTfR) in healthy newborns and to relate these iron indexes to iron status in the first 2 y of life.

Design: Using bivariate correlations and linear regression, we related various factors in pregnancy to SF (n=363) and sTfR (n=350) in healthy, term infants.