Lenka Malek Maria Makrides
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Pregnant and lactating women can largely meet their nutritional needs by following the gov- ernment-endorsed dietary guidelines available in most countries and adding some extra daily serv- ings of some core food groups [3, 4] . An example is provided in table 2 .
The remainder of the chapter outlines the cas- es of specific nutrients and special conditions in pregnancy and lactation.
Folic Acid
Periconceptional folic acid supplementation has been shown to reduce the first-time occurrence of neural tube defects (NTD) by up to 72% and reoc- currence by 68% [5] . The critical window for in- creasing folate intake for the prevention of NTDs is before neural tube closure, which normally oc- curs by day 28 after conception. Given it can take 3 weeks to increase serum folate towards adequa- cy, supplementation should commence at least 1 month before conception and continue until at least 1 month after conception, although up to 3 months is often advised. A daily folic acid dose of 400–500 μg is recommended for low-risk women (i.e. no family history of NTDs, not on anticon-
vulsants) and 4,000–5,000 μg for women with a personal or close family history of NTDs. See table 3 for natural and fortified sources of folate.
Iodine
Iodine is required for the production of thyroid hormones, which are essential for normal fetal and infant growth and brain development. Major fetal effects of severe iodine deficiency (ID) in- clude abortions, stillbirths, congenital abnormal- ities, increased perinatal and infant mortality and cretinism [6] . In an effort to prevent ID, salt iodi- sation has been implemented in nearly all coun- tries worldwide, and in countries where <20% of households have access to iodised salt, the WHO and UNICEF recommend iodine supplementa- tion for pregnant and lactating women.
Mild-to-moderate ID also occurs in many countries. Although its functional consequences are not well established, many countries recom- mend a daily supplement containing 150 μg of io- dine in preconception, pregnancy and lactation.
Iodine-fortified foods, including bread, are available in some countries. While iodine is also found naturally in certain foods ( table 3 ), the io-
Table 1. The 2009 Institute of Medicine gestational weight gain recommendations for singleton and twin pregnan- cies [2]
Pre-pregnancy BMI category Singleton pregnancy Twin pregnancy
total weight total weight gain mean rate (range) of weight gain in gain
the second and third trimesters
Underweight (<18.5) 28–40 lb 1.0 (1.0–1.3) lb/week –
12.5–18 kg 0.51 (0.44–0.58) kg/week – Normal weight (18.5–24.9) 25–35 lb 1.0 (0.8–1.0) lb/week 37–54 lb
11.5–16 kg 0.42 (0.35–0.50) kg/week 17–25 kg Overweight (25.0–29.9) 15–25 lb 0.6 (0.5–0.7) lb/week 31–50 lb
7–11.5 kg 0.28 (0.23–0.33) kg/week 14–23 kg
Obese (≥30.0) 11–20 lb 0.5 (0.4–0.6) lb/week 25–42 lb
5–9 kg 0.22 (0.17–0.27) kg/week 11–19 kg
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
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Table 2. Minimum recommended number of serves per day from core food groups for adult women as well as ad- ditional requirements for pregnant and lactating women
Food group Example serves Women Pregnant
women
Lactating women Grain (cereal) foods, mostly
wholegrain and/or high- cereal-fibre varieties
– 1 slice bread 6 +2.5 +3
– 1/2 medium roll or flat bread
– 1/2 cup cooked rice, pasta, noodles or other grains – 2/3 cup wheat cereal flakes
– 1/2 cup cooked porridge – 1/4 cup muesli – 3 (35 g) crisp breads
– 1 crumpet, small English muffin or scone
Vegetables and – 1/2 cup cooked green or orange vegetables 5 No change +2.5
legumes/beans – 1/2 cup cooked dried or canned legumes/beans – 1 cup green leafy or raw salad vegetables – 1/2 cup sweet corn
– 1/2 medium potato or other starchy vegetable – 1 medium tomato
Fruit – 1 medium piece (e.g. apple, banana) 2 No change No change
– 2 small pieces (e.g. apricots, kiwi fruit) – 1 cup diced or canned fruit (no added sugar) Or only occasionally:
– 1/2 cup fruit juice (no added sugar) – 30 g dried fruit (e.g. 4 dried apricot halves,
1.5 tablespoons of sultanas) Milk, yoghurt, cheese and/or
their alternatives, mostly reduced fat
– 1 cup (250ml) milk 2.5 +1 +1
– 1/2 cup evaporated unsweetened milk – 40 g (2 slices or 4 small cubes) hard cheese,
such as cheddar – 1/2 cup ricotta cheese – 3/4 cup (200 g) yoghurt
– 1 cup soy, rice or other cereal drink with at least 100 mg of added calcium per 100 ml
The following alternatives contain about the same amount of calcium as a serve of milk, yoghurt or cheese:
– 100 g almonds with skin – 60 g sardines, canned in water
– 1/2 cup (100 g) canned pink salmon with bones – 100 g firm tofu (check label as calcium levels vary) Lean meat and poultry, fish,
eggs, nuts and seeds as well as legumes/beans
– 65 g cooked lean red meats (~90 – 100 g raw) 2.5 +1 No change
– 80 g cooked lean poultry (~100 g raw) – 100 g cooked fish fillet (~115 g raw) or
1 small can of fish – 2 large eggs
– 1 cup (150 g) cooked or canned legumes/beans (preferably with no added salt)
– 170 g tofu
– 30 g nuts, seeds, peanut or almond butter or tahini, or other nut or seed paste
Values are given for women aged 19 – 50 years. Adapted from the Australian Dietary Guidelines [3].
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dine content can vary widely due to a number of factors including geographical location and envi- ronmental factors such as the iodine concentra- tion in the soil. Kelp and seaweed-based products should be avoided during pregnancy and lacta- tion due to their large variability in iodine con- tent.
Iron
Iron requirements increase in the second and third trimesters to support fetal growth, placental tissue development and expansion of the red cell mass. Intestinal iron absorption increases to meet
increased iron requirements, and reaches peak ef- ficiency during the third trimester, when the ma- jority of iron transfer occurs. In iron-sufficient pregnancies, enough iron is transferred to meet the infant’s iron requirements for the first 6 months of life. Maternal iron requirements are reduced during lactation and increase to pre- pregnancy levels when menstruation resumes.
Haem iron from animal sources is better ab- sorbed than non-haem iron from plant sources ( table 3 ). Iron absorption from plant foods can be increased by consuming meat proteins or a source of vitamin C (e.g. citrus fruits/juices, strawber- ries, kiwi fruit, tomatoes and broccoli) at the same meal. Dietary components which can in-
Table 3. Animal-derived, plant-derived and fortified sources of key nutrients
Animal-derived sources Plant-derived sources Fortified sources
(available in some countries) Folate Boiled egg yolk Green leafy vegetables, oranges,
orange juice, grapefruit, strawberries, raspberries, blackberries, sultanas, yeast spread (Marmite, Vegemite), legumes, peanuts, sesame seeds, tahini, sunflower seeds
Bread, breakfast cereals, flavoured beverage bases (e.g. Milo), milk, soy beverages, fruit juice
Iodine Fish/seafood, milk, yogurt, cheese, eggs
Seaweed;
minimal amounts in other sources
Bread, iodised salt Iron Meat, poultry, fish/seafood
(haem-iron) Eggs (non-haem iron)
Cooked legumes (chickpeas, lentils, kidney and lima beans), wholegrain breads and cereals, nuts, seeds, dried fruit and green leafy vegetables (non-haem iron)
Breakfast cereals, flavoured beverage bases (e.g. Milo; non-haem iron)
Calcium Milk, cheese, yogurt, fish with bones (e.g. salmon, sardines), fish paste/spread, crab meat
Amaranth, grain-based foods, green leafy vegetables, almonds, Brazil nuts, sesame seeds, tahini, soybeans, firm tofu, dried fruit
Soy/oat/rice/nut beverages, soy yogurt, tofu, breakfast cereals, fruit/vegetable juice, flavoured beverage bases (e.g. Milo), bread, edible oil spreads
Vitamin D Oily fish, egg yolks Mushrooms Margarines, milk, powdered milk,
soy beverages, yogurt, cheese, eggs, breakfast cereals, orange juice Vitamin B12 Meat, poultry, fish/seafood,
milk, cheese, yogurt, eggs
None Soy beverages, veggie burgers,
soy-based meat analogues and yeast extracts (e.g. Marmite)
Zinc Meat, poultry, eggs, milk, cheese, yogurt, cooked seafood (especially oysters)
Legumes, wholegrain breads and cereals, brown rice, soy products (e.g. tofu and tempeh), nuts, seeds
Breakfast cereals
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
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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] .
Calcium
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.
Vitamin 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.
Multifetal Pregnancies
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
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infant. To avoid a deficiency, some animal-de- rived foods or vitamin B 12 -fortified foods should be consumed or a vitamin B 12 supplement taken.
An adequate intake of iron, zinc, calcium and protein should also be ensured. Vegetarian sourc- es of protein include dairy foods, legumes, cere- als and grains as well as nuts and seeds. Vegetar- ian sources of iron, zinc and calcium are shown in table 3 .
Mercury in Fish
Fish is an important part of a healthy diet. It pro- vides long-chain omega–3 fatty acids and is a good source of protein and minerals including io- dine. Mercury is a neurotoxin which occurs natu- rally in the environment and accumulates in fish.
The consumption of fish during pregnancy and lactation should be guided by national, govern- ment-endorsed recommendations, which gener- ally advise eating 2–3 meals per week of fish/shell- fish with low mercury levels and avoiding or lim- iting the consumption of fish high in mercury (predatory deep-sea fish) [9, 10] . Canned fish generally has lower levels of mercury, as smaller species and younger fish are used for canning.
Herbal Teas and Herbal Supplements
There is insufficient evidence to support the con- sumption of herbal teas or herbal supplements during pregnancy or lactation. Most herbal prep- arations have not been tested to establish their ef- ficacy and safety, and some may be dangerous to the developing fetus or infant.
Listeriosis
Listeriosis is a rare but serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes . The transmission of lis-
teria to the fetus can cause miscarriage, prema- ture labour or stillbirth. The risk of listeriosis can be reduced by avoiding high-risk foods and tak- ing simple food hygiene and food safety steps.
Foods to avoid include chilled, ready-to-eat foods such as cold cooked chicken, cold processed meats, pre-prepared or pre-packed cold salads, raw seafood, soft-serve ice cream, unpasteurised dairy products, pâté as well as soft and semi-soft cheese.
Caffeine (Coffee, Tea and Caffeine Soft Drinks)
Some caffeine is transferred to the fetus via the placenta and to the infant via breast milk. A daily intake of 200–300 mg caffeine, equivalent to 2–3 cups of coffee, is considered to have no adverse effect. Energy drinks are not recommended as they can contain high levels of caffeine.
Alcohol
Alcohol is transferred to the fetus via the placenta and to the infant via breast milk. There is no safe limit for alcohol intake, and it is recommended that alcohol consumption be avoided during pregnancy. During lactation, the alcohol content of breast milk reflects maternal blood alcohol levels. As a general rule, it takes an average-sized woman 2 h for blood alcohol levels to return to zero after consuming 10 g of alcohol (1 standard drink). Therefore, women who plan to consume alcohol should breastfeed or express breast milk before drinking.
Conclusions
• Nutrition in pregnancy can exert important short- and long-term effects on the mother and baby
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
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• The increased nutritional requirements dur- ing pregnancy can generally be met by eating a wide variety of foods according to the relevant government guidelines
• Specific supplementation for folate to prevent NTD is widely recommended
• Recommendations for other nutrients like io- dine and iron are more country and region specific
8 Goodnight W, Newman R; Society of Maternal-Fetal Medicine: Optimal nutri- tion for improved twin pregnancy out- come. Obstet Gynecol 2009; 114: 1121–
1134.
9 Food Standards Australia New Zealand:
Mercury in fish. 2011. www.foodstan- dards.gov.au/consumer/chemicals/
mercury/Pages/default.aspx.
10 US Food and Drug Administration, US Environmental Protection Agency:
What you need to know about mercury in fish and shellfish: advice for women who might become pregnant, women who are pregnant, nursing mothers, young children. 2004. www.fda.gov/
food/resourcesforyou/consumers/
ucm110591.htm.
References
1 Osmond C, Barker DJP: Fetal, infant, and childhood growth are predictors of coronary heart disease, diabetes, and hypertension in adult men and women.
Environ Health Perspect 2000; 108: 545–
553.
2 Institute of Medicine (US) and National Research Council (US) Committee to Reexamine IOM Pregnancy Weight Guidelines; Rasmussen K, Yaktine A (eds): Weight Gain during Pregnancy:
Reexamining the Guidelines. Washing- ton, National Academies Press, 2009.
3 National Health and Medical Research Council: Australian Dietary Guidelines.
Canberra, National Health and Medical Research Council, 2013.
4 US Department of Agriculture, US De- partment of Health and Human Servic- es: Dietary Guidelines for Americans, 2010, ed 7. Washington, US Govern- ment Printing Office, 2010.
5 De-Regil LM, Fernández-Gaxiola AC, Dowswell T, Peủa-Rosas JP: Effects and safety of periconceptional folate supple- mentation for preventing birth defects.
Cochrane Database Syst Rev 2010;
10:CD007950.
6 Hetzel BS: Iodine deficiency disorders (IDD) and their eradication. Lancet 1983; 2: 1126–1129.
7 WHO: Guideline: daily iron and folic acid supplementation in pregnant wom- en. Geneva, WHO, 2012.
2 Nutrition of Healthy Infants, Children and Adolescents
Key Words
Vegetarian diet ã Vegan diet ã Nutrient deficiencies
Key Messages
• Carefully planned mixed vegetarian diets (with milk and eggs) can provide sufficient energy, protein and nutrients for all stages of childhood growth and development
• Very restrictive or unbalanced vegetarian diets can result in failure to thrive and serious nutrient defi- ciencies in infants and children
• Vegan diets pose the highest risk for nutrient defi- ciencies in childhood, particularly for energy, pro- tein, essential fatty acids, vitamin B 12 , vitamin D, iron, calcium and zinc
• Practical dietary advice should include alternative dietary sources of nutrients and supplementation of the diet where clinically indicated
© 2015 S. Karger AG, Basel
Introduction
Guidance on nutrient intakes to support optimal growth and development in vegetarian infants, children and adolescents is identical to that for non-vegetarians (see Annex 4.3). Vegetarian chil-
dren can meet all nutritional needs for growth and development, provided the diet is well de- signed, balanced and appropriate to the stage of development. Vegetarianism is used to describe a range of highly diverse eating patterns, broadly characterised by the degree of restriction of ani- mal products, as shown in table 1 . Semi- and lac- to-(ovo-)vegetarian diets containing milk prod- ucts, eggs and/or fish can easily provide adequate nutrients throughout all life stages. However, there is a greater risk for nutritional deficiencies, especially for energy, protein, n–3 fatty acids, vi- tamin B 12 , vitamin D, calcium, iron and zinc, in children eating more restrictive vegan diets.
Vegetarians tend to consume less saturated fat and a higher amount of fibre and micronutrients compared to omnivores [1] . Health benefits, such as low rates of obesity and reduced risk of coro- nary heart disease and diabetes, have been asso- ciated with a vegetarian diet in adults [2] but are less established in children, although vegan chil- dren do tend to be leaner than their omnivorous peers [3] .
The main challenges for paediatric care clini- cians are to assess the quality of the vegetarian diet, to determine the likely risk for nutritional de- ficiency and to offer dietary education and family
Koletzko B, et al. (eds): Pediatric Nutrition in Practice. World Rev Nutr Diet. Basel, Karger, 2015, vol 113, pp 134–138 DOI: 10.1159/000367873