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Getting the right nutrition during breastfeeding

A healthy, varied diet is important during breastfeeding, and even more nutrients are required than during pregnancy. Women require an extra 330kcal per day (1.4MJ per day) in the first six months of lactation if exclusively breastfeeding, and it is important that the extra energy consumed is nutrient-dense to meet the needs of both the mother and her developing baby.

The maternal diet can influence the long-chain fatty acids and vitamin content of breastmilk. Maternal stores of some nutrients such as iron and Omega-3 fatty acids may be low in the mother after pregnancy and in need of replenishing.

There are several important micronutrients for breastfeeding women in particular, as increased amounts are required (e.g. vitamin A, vitamin D, vitamin B2, vitamin B12, folate, calcium, magnesium and zinc). As in pregnancy, a daily supplement of vitamin D is also required for breastfeeding women.

This article discusses the importance of getting the right nutrition during breastfeeding, the extra energy requirements, maternal nutrient stores in need of replenishing and key nutrients for breastfeeding women.

 

Introduction

Breastfeeding women need even more nutrients than when pregnant. When breastfeeding, women require an increased intake of the following micronutrients: vitamin A, vitamin D, vitamin B1, B2, B3, B12, folate, vitamin C, calcium, magnesium, zinc, phosphorous, copper and selenium1. Adequate levels of these nutrients can be obtained by eating a healthy, varied diet, with the exception of vitamin D (see section on key nutrients).

Exclusive breastfeeding is recommended for the first six months. Breastmilk provides all the nutrients a baby needs during this period, in a form that is hygienic and easy to digest. Breastmilk also contains a range of bioactive components, including antimicrobial and anti-inflammatory factors, digestive enzymes, hormones and growth factors2. For example, growth factors found in human milk are thought to be important for gut maturation, and lactoferrin (an antimicrobial factor) is one of several specific binders in human milk that greatly increases the bioavailability of iron2.

Both the volume and composition of breastmilk vary with the stage of lactation, within each individual feed and with maternal nutrition status. Although the mother’s macronutrient intake (protein, fat, carbohydrate) does not have much influence on milk composition, her diet does affect the long-chain fatty acid and vitamin content of her milk3. The flavour of foods is also transferred from mother to baby via breastmilk4, which may influence the infant’s acceptance of new foods during weaning and early feeding experiences.

 

Extra energy required

The extra energy demand during breastfeeding was calculated to be around 500kcal per day (2.1 MJ per day) by COMA (Committee on Medical Aspects of Food Policy) in 1991, although it was recognised to vary with the extent of breastfeeding and the age of the child1. More recently, SACN (Scientific Advisory Committee on Nutrition) has recommended the use of the US Energy DRI (Dietary Reference Intake)5 of 330kcal per day (1.4MJ per day) in the first six months of lactation, if exclusively breastfeeding. After the first six months, the energy intake required to support breastfeeding will be modified by maternal body composition and the breastmilk intake of the infant6.

 

Nutrient stores to replenish

Maternal stores of some nutrients may need to be replenished after pregnancy. Stores of iron and Omega-3 fatty acids in particular, may be low in the mother, and adequate folate in the maternal diet during breastfeeding is important to maintain maternal folate levels. These nutrients are discussed further below.

Iron

Iron intakes among women of childbearing age are frequently below recommended levels; in women aged 19–64, 23% have intakes below the LRNI (Lower Reference Nutrient Intake) for iron; the situation is far worse among girls aged 11–18, in whom the prevalence rate is 46%7. Although there is no national data on iron intakes or prevalence of iron deficiency in pregnant women in the UK, several small British studies suggest that intakes below reference levels are evidence of the wider situation3. It may take around 18 months for maternal iron stores to be replenished8.

Red meat is an important source of iron, and plant-derived foods containing iron (e.g. wholegrain products, pulses, beans, nuts, dark green leafy vegetables) should be consumed along with foods or drinks containing vitamin C (e.g. fruits, fruit juice or vegetables) to help iron absorption (e.g. a glass of fresh orange juice with cereal for breakfast).

Folate

Women need 200µg of folate per day and an extra 60µg per day if breastfeeding1. Folate is one of the nutrients commonly found to be low in the diets of breastfeeding women3. Evidence suggests that folate levels in breastmilk are maintained at the expense of maternal folate reserves9. While this protects the infant, the nutrient status of the mother and the impact on subsequent pregnancies would be of concern. Breastfeeding women should consume plenty of foods containing folate and folic acid (the synthetic form of folate) to ensure adequate levels. See table 1.

Omega-3 fatty acids

The brain and other neural tissue, including the retina, are largely composed of phospholipids which are rich in long-chain polyunsaturated fatty acids, especially the long-chain Omega-3 fatty acid docosahexaenoic acid (DHA)3. The fetus and newborn baby are dependent on a maternal supply of DHA10. Rapid brain development occurs during the last trimester of pregnancy and the first year after birth. As a consequence of the increased demand on maternal DHA supplies, it is thought that maternal DHA supplies are likely to be depleted over pregnancy, and successive pregnancies and periods of lactation may reduce levels further11,12.

The levels of DHA in breastmilk can vary widely, depending on the mother’s diet. DHA levels in breastmilk have been found to be higher in women who eat fish13. Oil-rich fish are the main dietary source of the long-chain Omega-3 fatty acids DHA and EPA (eicosapentaenoic acid). In the UK, adults are recommended to eat at least two portions (140g each) of fish, one of which should be an oil-rich fish (e.g. salmon, mackerel, trout, herring and sardines). This equates to approximately 450mg of long-chain Omega-3 fatty acids per day or 3.2g per week10.

Findings from two large, EU-funded research projects (PeriLip and EARNEST) led to the conclusion that pregnant and breastfeeding women should have an intake of at least 200mg DHA per day14. This intake can be reached with the consumption of one to two portions of fish per week, including oil-rich fish. The European Food Safety Authority (EFSA) suggests adults should have an average daily intake of 250mg of the long-chain Omega-3 fatty acids EPA and DHA combined15. EFSA also suggests that pregnant and breastfeeding women should increase their intake of preformed DHA by 100–200g per day (in addition to the suggested average intake of 250mg of EPA + DHA combined)15. An intake of one to two portions of oil-rich fish per week should be compatible with an adequate DHA supply during pregnancy and lactation15. Pregnant and breastfeeding women are advised not to eat more than two portions of oil-rich fish per week to reduce exposure to pollutants and heavy metals including mercury, which may harm a baby’s development during pregnancy or breastfeeding.

 

Key nutrients during breastfeeding

A healthy, varied diet is important to ensure an adequate intake of nutrients. Breastfeeding women require extra amounts of some nutrients such as the vitamins A, D, B2 and B12, folate (discussed above) and the minerals calcium, magnesium and zinc. Further details of these nutrients and other key nutrients are discussed below. Table 2 shows the prevalence of low intakes of selected micronutrients. The latest National Diet and Nutrition Survey published in May 2014 indicates that nutrient intakes among teenagers and younger women are generally poorer compared with older women of childbearing age7.

Vitamin A

Vitamin A is essential for normal structure and function of skin. It is also vital for vision, growth and a healthy immune system. Breastfeeding women require an additional 350µg per day of vitamin A (on top of the 600μg per day required by adult women)1. Sources of vitamin A include cheese, butter, margarine and reduced fat spreads (vitamin A is often voluntarily added to reduced fat spreads). Carotenoids such as beta-carotene can be converted to vitamin A in the body. Dietary sources of carotenoids include dark green leafy vegetables and orange-coloured fruits (such as mangoes and apricots). The average daily intake of vitamin A among women aged 19–64 is 944μg, with around 1 in 20 (5%) adult women having intakes below the LRNI7.

Vitamin D

Vitamin D helps the body absorb calcium from the diet which is important for healthy bones and teeth. Many women in the UK have a low vitamin D status, which if severe, puts them at risk of osteomalacia (the adult form of rickets). The main source of vitamin D is through the action of sunlight on the skin during the summer months. Those who are at particular risk of low vitamin D status include those who have darker skin, those who rarely go outside, those who cover their skin with clothing or sunscreen and those who avoid animal foods or who have a very poor diet16. A daily vitamin D supplement of 10µg is recommended for breastfeeding (and pregnant) women1.

Vitamin B2

Vitamin B2 helps release energy from food and helps maintain the health of mucous membranes like those in the mouth and intestines. Adult women require 1.1mg per day of vitamin B2, but breastfeeding women need an extra 0.5mg per day on top of this1. This extra amount of vitamin B2 can be found in a small bowl of fortified breakfast cereal. Many women get most of their vitamin B2 from animal sources, especially dairy foods (e.g. milk, cheese, yoghurt). For other food sources see table 1. Around one in ten (12%) women aged 19–64 have average daily vitamin B2 intakes below the LRNI7.

Vitamin B12

Vitamin B12 helps make red blood cells and keeps the nervous system healthy. Breastfeeding women need an additional 0.5μg a day to the 1.5μg vitamin B12 required by adult women1. Vitamin B12 is found in almost all foods of animal origin, for example, meat, fish, poultry, eggs, milk and milk products, as well as yeast extract and fortified breakfast cereals. The current average daily intake of vitamin B12 among adult women aged 19–64 is 4.6μg7. However, vegetarian diets that contain only small amounts of dairy products and eggs and vegan diets are likely to be lacking in vitamin B12 (and may be also be low in calcium, vitamin B2, iron and vitamin D)3.

Calcium

Calcium is important for the mother to maintain her bone density. Calcium demands on the mother are high during the later stages of pregnancy and during lactation. During lactation, approximately 250mg of calcium is secreted in breastmilk each day17. Most breastfeeding women increase their food intakes and hence their calcium intakes, thus providing the additional calcium required for milk production1. Women need 700mg of calcium per day, with an extra 550mg per day required by breastfeeding women1. A slice of toast with cheese and a glass of milk provides around 550mg of calcium. For other foods providing calcium, see table 1.

Young mothers may require additional calcium for their own growth as peak bone mass is reached in the twenties18. In terms of dietary supply, a significant proportion of young women have an average calcium intake below the LRNI (19% of girls aged 11–18 and 8% of women aged 19–64)7. Vitamin D is required for calcium absorption and therefore it is important that the recommended supplement of 10µg of vitamin D is adhered to by breastfeeding women.

Magnesium

Magnesium is important for bone health, muscle and nerve function. Adult women need 270mg of magnesium per day and an additional 50mg per day during breastfeeding1. Magnesium is present in both plant and animal cells and is widely available in foods. The main dietary sources are cereals and cereal products, providing between 28–33% of magnesium intakes among all age groups of the population, although milk and milk products, vegetables and potatoes and meat and meat products also contribute to magnesium intake7. The latest National Diet and Nutrition Survey reported average daily intakes of magnesium below the LRNI for 11% of women aged 19–64 and over half (53%) of girls aged 11–187.

Zinc

Zinc is important for growth and repair and for normal reproductive development. It is also beneficial for the immune system and for wound healing. Adult women require 7mg per day of zinc and an additional 6mg per day during breastfeeding1. Zinc is found in many foods, including red meat (which contributes to around a third of zinc intakes), milk, cheese, eggs, shellfish, wholegrain cereals, nuts and pulses. The current average daily zinc intake among women aged 19–64 is 7.6mg7. It is therefore important to ensure women eat plenty of foods containing zinc to meet the additional zinc requirements when breastfeeding.

Iodine

Iodine helps make the thyroid hormones. These hormones are needed for many body processes including growth, regulating metabolism and for the development of a baby’s brain during early life. The WHO iodine requirement for breastfeeding women is 250μg per day. The UK Reference Nutrient Intake (RNI) for pregnant women is 140μg per day, which is the same as for non-pregnant women1.

It is important for breastfeeding women to have adequate iodine intakes so that their breastmilk has enough iodine to meet the baby’s needs, particularly for the baby’s brain development19.

Iodine is found in a variety of foods (see table 1). The major dietary source of iodine in the UK diet is milk and milk products, which contribute to 35% of iodine intake in women aged 19–647. A small glass (200ml) of cow’s milk contains 50–80μg of iodine; an egg contains 20μg and a portion (40g) of cheese 15μg of iodine19. It is important to note that organic milk has a 40% lower iodine content than conventional milk19. The actual amount of iodine in food and milk varies according to the iodine content of the soil, farming practice and season19,23.

Those who are most at risk of iodine deficiency includes anyone who avoids fish and/or dairy products (e.g. due to allergy or intolerance), vegetarians and, particularly, vegans since they do not eat rich iodine sources (fish and/or dairy products)19.

Protein

Adult women (aged 19–50 years) require approximately 45g of protein a day. Breastfeeding women require an additional 11g of protein a day during the first four months which reduces to an additional 8g per day, when breastfeeding longer than four months1. The current average daily protein intake among women in the UK is 65g, which is well above the RNI7. Therefore, most women do not need to consume additional protein during breastfeeding.

 

Table 1: Summary of nutrients of particular significance during breastfeeding

Nutrient RNI for women aged 19-50 years Current picture among women in the UK Practical messages Food sources
Non- breast
feeding
Breast
feeding
Iron 14.8mg/day No increment Poor iron status in pregnancy is common in the UK, so it is important to replenish iron stores after the baby is born. Consume plenty of iron-rich foods, preferably with a food or drink containing vitamin C for enhancing iron absorption from non-heam sources. Red meat, beans, dried fruit, nuts, wholegrains, fortified breakfast cereals, dark green vegetables.
Folate 200µg +60µg Average intakes of folate among UK women aged 19–24 and 25–34 respectively, were 248 and 249µg per day24. Folate is one of the nutrients commonly found to be low in the diets of breastfeeding women25. Evidence suggests that folate levels in breastmilk are maintained at the expense of maternal folate reserves, so it’s important for breastfeeding women to include plenty of foods containing folate/folic acid to maintain supplies. Foods that contain folate/folic acid include green leafy vegetables, peas, oranges, bananas, beans, wholegrain products, nuts and fortified breakfast cereals.
DHA* 450mg/day** >200mg Intakes of DHA in the UK were estimated to be around 100mg per day for adult women and for those who do not consume fish, or are consuming a low-fat diet, the intake is likely to be substantially less26. An intake of one to two portions of oil-rich fish per week should be an adequate DHA supply during pregnancy and lactation27. Oil-rich fish are the main food source of the long-chain Omega-3 fatty acids. Eggs can also provide a significant contribution to intake of DHA.
Vitamin A 600µg/day +350µg/day 5% of women aged 19–64 years have vitamin A intakes below the LRNI and 14% of adolescent girls (aged 11–18 years) have intakes below the LRNI28. Liver is a particularly rich source of vitamin A, but too much vitamin A can harm the unborn baby. Liver and liver products should not be eaten more than once a week29. Cheese, butter, margarine, reduced fat spreads (vitamin A is often added to reduced fat spreads). Carrots, dark-green leafy vegetables and orange-coloured fruits are dietary sources of beta-carotene, which the body can convert to vitamin A.
Vitamin D 10µg No increment The current average dietary intake of vitamin D among women aged 19–64 is 2.6μg28. The main source of vitamin D is through the action of sunlight on the skin. About 10–15 minutes of skin exposure to the sun is enough for most lighter-skinned people to obtain adequate daily vitamin D29. Oily fish, eggs, fortified foods including breakfast cereals, some fortified dairy products and fat spreads.
Vitamin B2 1.1mg/day +0.5mg/day Around one in ten (12%) women aged 19–64 have average daily vitamin B2 intakes below the LRNI24. Many women get most of their vitamin B2 from animal sources and particularly dairy foods, so if they avoid these foods it is important that they include non-animal sources of vitamin B2. Milk, eggs, fortified breakfast cereal, legumes (peas, beans, and lentils), mushrooms and green vegetables.
Vitamin B12 1.5µg +0.5µg The current average daily intake of vitamin B12 among adult women aged 19–64 is 4.6μg28. Vegetarian diets that contain only small amounts of dairy products and eggs and vegan diets are likely to be lacking in vitamin B12. Meat, fish, shellfish, eggs, milk, fortified breakfast cereals, yeast extract.
Calcium 700mg +550mg A significant proportion of young women have an average calcium intake below the LRNI (19% of girls aged 11–18 and 8% of women aged 19–64) indicating these intakes are inadequate28. Calcium is most readily absorbed from milk and dairy products. Milk, cheese, yoghurt are rich sources, but calcium is also found in fish with edible bones, such as sardines, some fortified breakfast cereals (check the labels), dried fruit, bread, almonds, calcium-fortified soya drinks and tofu and green leafy vegetables.
Magnesium 270mg +50mg 11% of women aged 19–64 years have magnesium intakes below the LRNI and over half (53%) of adolescent girls (aged 11–18 years) have intakes below the LRNI28. The main dietary sources of magnesium are cereals and cereals products, providing between 28–33% of magnesium intakes28. Sources include green leafy vegetables, nuts, bread, fish, meat and dairy products.
Zinc 7mg +6mg The current average daily zinc intake among women aged 19–64 is 7.6mg. Around 1 in 5 (22%) girls aged 11–18 have zinc intakes below the LRNI compared with 4% of women aged 19–6428. Zinc is most readily available from red meat. For cereals and pulses, zinc availability is limited by phytates. Found in many foods including red meat, milk, cheese, eggs, shellfish, wholegrain cereals, nuts and pulses.
Iodine 140µg No increment Around one in five (22%) girls aged 11-18 years and one in ten (10%) women aged 19–64 years have average daily iodine intakes that fall below the lower reference nutrient intake (LRNI) of 70μg per day28. It is important for breastfeeding women to include iodine-containing foods in her diet to ensure her breastmilk provides adequate iodine for the baby’s brain development. Rich sources include sea fish and shellfish, but milk and dairy products are also major contributors.

Table 1: Notes
RNI: Reference Nutrient Intake; DHA: docosahexaenoic; LRNI: Lower Reference Nutrient Intake
* Long-chain Omega-3 fatty acid
**450mg/day of Omega-3 fatty acids equates to two portions of fish per week, one of which should be an oil-rich fish

 

Table 2: Percentage of participants with average daily intakes of vitamins and minerals from food sources below the Lower Reference Nutrient Intake (LRNI), by age

Nutrient Girls aged
11-18 years (%)
Women aged
19-64 years (%)
Vitamin A 14 5
Vitamin B12 2 2
Folate 8 4
Iodine 22 10
Iron 46 23
Calcium 19 8
Zinc 22 4
Selenium 46 51
Magnesium 53 11
Potassium 33 23

Table 2 source: Bates et al, (2014) 

 

Conclusion

Good nutrition is important during breastfeeding to optimise the health of the woman and her developing baby, both in the short- and long-term.

A healthy, varied diet is important among breastfeeding women, as diet can impact the nutritional content of breastmilk. The nutritional requirements for breastfeeding women are even greater than for pregnant women.

Most of the increased maternal nutrient requirements can be achieved by consuming a healthy, varied diet, although a daily vitamin D supplement is recommended for women throughout breastfeeding. Particular attention should be taken with some nutrient intakes, as maternal stores are likely to be low following pregnancy.

Some specific groups of the population (e.g. teenage girls and young women and women from low-income groups) have a higher risk of poor nutrient intake of some nutrients and health professionals should give particular attention to the diet and nutrient advice for such groups, to ensure optimal nutrition and health for both the mother and her baby.

 

Practical dietary advice

Good nutrition is important during breastfeeding to optimise the health of the woman and her developing baby, both in the short- and long-term.

A healthy, varied diet is important among breastfeeding women, as diet can impact the nutritional content of breastmilk. The nutritional requirements for breastfeeding women are even greater than for pregnant women.

Most of the increased maternal nutrient requirements can be achieved by consuming a healthy, varied diet, although a daily vitamin D supplement is recommended for women throughout breastfeeding. Particular attention should be taken with some nutrient intakes, as maternal stores are likely to be low following pregnancy.

Some specific groups of the population (e.g. teenage girls and young women and women from low-income groups) have a higher risk of poor nutrient intake of some nutrients and health professionals should give particular attention to the diet and nutrient advice for such groups, to ensure optimal nutrition and health for both the mother and her baby.

  • Eat plenty of fruit and vegetables – foods you eat whilst breastfeeding (and during pregnancy) may influence the baby’s taste preferences. Eating a wide variety of fruit and vegetables may help increase the baby’s acceptance of fruit and vegetables when weaning.
  • Eat fish twice a week (one of these portions should be an oily fish). Oily fish are particularly rich in long-chain Omega-3 fatty acids, which the baby requires for healthy development of the brain, eyes and nerves. The mother is likely to have low supplies of beneficial long-chain Omega-3 fatty acids due to the baby’s increased demand during pregnancy, so including 1–2 portions of oil-rich fish per week is important.
  • Include plenty of starchy foods such as wholemeal bread, pasta, rice and potatoes – fibre found in wholegrain foods and fruit and vegetables can help reduce bowel problems and constipation some women experience after childbirth.
  • Keep hydrated – breastfeeding women need an extra 700ml (3–4 glasses) of fluid in addition to the 6–8 glass recommendation for adults. It’s useful for women to have a drink beside them when breastfeeding.
  • Limit caffeine intake as drinks containing caffeine can affect the baby and keep them awake. Caffeine can be found in many foods and drinks such as coffee, tea, some soft drinks and chocolate. Try decaffeinated tea and coffee, herbal teas or water.
  • Limit or avoid alcohol when breastfeeding. Alcohol passes through to breastfed babies in very small amounts. An occasional drink is unlikely to harm the mother or her baby, but it might affect how easily the baby feeds, so it is sensible to drink very little (no more than 1–2 units once or twice a week).

Some women can obtain free supplements via the government’s Healthy Start scheme. The vitamins for women contain folic acid, vitamin C and vitamin D. These supplements should be available from health centres and or pharmacies. Ask your GP or visit the NHS Healthy Start website.

Some women can obtain Healthy Start vouchers every week to spend on milk, fresh or frozen vegetables and fruit, and infant milk formula. For more details visit the NHS Healthy Start website.

 

About the author

Dr Laura Wyness (BSc, MSc, PhD, RNutr)
Dr Wyness currently works as a Senior Research Fellow at Queen Margaret University, Edinburgh. She obtained her BSc, MSc and PhD from the University of Aberdeen before working as a researcher at Trinity College Dublin and at the Women’s Health Council in Dublin, conducting literature reviews and effectively communicating scientific research to a wide range of audiences. More recently, Dr Wyness worked at the British Nutrition Foundation in London as a Senior Nutrition Scientist. Her work included contributing to and editing a Task Force report entitled ‘Nutrition and Development: short- and long-term consequences for health’. She also developed a Healthy Life Planner for Women, which provides nutrition information for women, particularly around the time of pregnancy. Dr Wyness is a Registered Public Health Nutritionist with the Association for Nutrition and a member of the Nutrition Society Public Health Nutrition Theme Team.

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