Pediatric Nutrition in Practice

Nutrition in Pregnancy and Lactation 131

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hibit the absorption of both haem and non-haem
iron include calcium, zinc and phytates found in
legumes and whole grains. Polyphenols found in
tea and coffee can also inhibit non-haem iron ab-
sorption. This may have special significance for
vegetarians who also consume tea and coffee as
part of their daily diets.
While routine iron supplementation during
pregnancy is not common practice in all coun-
tries, the WHO recommends daily oral iron sup-
plementation (30–60 mg of elemental iron) as
part of antenatal care to reduce the risk of low
birth weight, maternal anaemia and iron defi-
ciency. A daily dose of 60 mg of elemental iron is
recommended in settings where the prevalence of
anaemia in pregnancy is ≥ 40%, and 120 mg is
recommended when there is a clinical diagnosis
of anaemia [7].

C a l c i u m

Calcium is required for fetal and infant bone de-
velopment and mineralisation, as well as for
breast milk production. Maternal bone turnover
and the intestinal absorption of calcium increase
during pregnancy to help meet fetal calcium re-
quirements. The majority of calcium is trans-
ferred to the fetus in the third trimester. During
lactation, calcium from the mother’s bones is
transferred to the infant via breast milk. This
bone resorption is independent of the calcium in-
take and is completely reversible, with the bone
density being restored 6–12 months after the ces-
sation of breastfeeding.
The recommended daily intake of calcium
during pregnancy and lactation is 1000 mg for
adults and 1,300 mg for adolescents. This can be
provided by 3–4 serves of calcium-rich foods
(each serve providing approx. 300 mg of calci-
um). Dietary sources of calcium are shown in ta-
ble  3. Calcium supplements should be taken if
dairy intake is low or if the intake from other
sources is inadequate.

V i t a m i n D

Vitamin D is important for regulating calcium and

phosphorus metabolism. A deficiency during

pregnancy has been associated with impaired cal-

cium and skeletal homoeostasis, congenital rickets

and fractures in the newborn. Vitamin D 3 (chole-

calciferol) is synthesised in skin cells upon expo-

sure to UVB radiation from sunlight, and adequate

exposure to sunlight can provide most people with

their daily vitamin D requirement. Vitamin D can

also be obtained through the diet from a limited

range of natural sources and variably fortified

foods available in some countries ( table 3 ).

Darker-skinned women and those with limited

exposure to sunlight are less likely to synthesise

sufficient vitamin D. Women at risk of deficiency

should be screened for low serum 25-hydroxyvita-

min D levels and supplemented as required.

M u l t i f e t a l P r e g n a n c i e s

In addition to the usual maternal physiological

adaptations that occur with singleton pregnan-

cies, in multifetal pregnancies there is an addi-

tional increase in plasma volume, basal metabolic

rate and resistance to carbohydrate metabolism

[8]. Higher intakes of protein, calcium, iron and

folate are required to support fetal and placental

growth and increased maternal metabolism.

Vegetarian Diets

Vegetarian diets vary, and identifying which

foods are excluded will help determine which nu-

trients are likely to be inadequately supplied. Vi-

tamin B 12 is an essential nutrient which only oc-

curs naturally in animal-derived foods. There-

fore, diets low in or excluding animal products

can be low in vitamin B 12. Vitamin B 12 deficiency

during pregnancy and lactation can cause mega-

loblastic anaemia and neurological damage in the

Koletzko B, et al. (eds): Pediatric Nutrition in Practice. World Rev Nutr Diet. Basel, Karger, 2015, vol 113, pp 127–133
DOI: 10.1159/000367872