folate-eng.pdf

ACKNOWLEDGEMENT

Health Canada sincerely thanks the members of the Expert Advisory Group on National Nutrition

Pregnancy Guidelines who generously gave their time and expertise over the course of preparing

these guidelines:

Aline Allain-Doiron, RD, Public Health Nutritionist-Dietitian, Regional Health Authority B, Zone 7

Andrée Gruslin, MD, FRCS, Director of the Post-graduate Residency Training Program in

Obstetrics and Gynaecology, University of Ottawa

Sheila M. Innis, RD, PhD, Director of Nutrition Research Program, Child and Family Research

Institute, University of British Columbia

Kristine G. Koski, RD, PhD, Director School of Dietetics and Human Nutrition, McGill University

Michel Lucas, PhD, MPH, RD, Epidemiologist/Nutritionist, Axe Santé des populations et

environnement, Centre Hospitalier de l’Université Laval (CHUL-CHUQ)

Ann Montgomery, RM, associate midwife and preceptor, Midwifery Collective of Ottawa

Deborah L. O’Connor, RD, PhD, Director of Clinical Dietetics, The Hospital for Sick Children, and

Associate Professor, Department of Nutritional Sciences, University of Toronto

Kay Yee, RD, Public Health Nutritionist, Regina Qu’Appelle Health Region

Health Canada would also like to thank the many stakeholders who took part in the online

consultation process and provided feedback on draft content of the guidelines.

<galement offert en français sous le titre :

Lignes directrices sur la nutrition pendant la grossesse à l’intention des professionnels de la

santé - Le folate contribue à une grossesse en santé

2009

This publication may be reproduced without permission provided the source is fully

acknowledged.

Cat.: H164-109/2-2009E-PDF

ISBN: 978-1-100-12208-3

Prenatal Nutrition Guidelines for Health Professionals

Folate Contributes to a Healthy Pregnancy

Folate

, a B vitamin, plays an important role in cell division and in the synthesis of amino

acids and nucleic acids like DNA (Antony, 2007).

It is essential to the normal

development of the spine, brain and skull of the fetus, especially during the first four

weeks of pregnancy. This is a time when many women are not yet aware that they are

pregnant. Folate also supports the pregnant woman’s expanding blood volume and

growing maternal and fetal tissues (IOM, 1998).

KEY MESSAGES ON FOLATE FOR WOMEN OF CHILDBEARING AGE

• Eating according to Canada’s Food Guide and taking a daily multivitamin that has

400 mcg (0.4 mg) of folic acid will help you prepare for a healthy pregnancy. Doing

this can also reduce the risk to your baby of developing a neural tube defect

(NTD).

• Make sure your supplement contains vitamin B

• Because many pregnancies are unplanned, all women who could become

pregnant should take a daily multivitamin containing 400 mcg (0.4 mg) of folic acid.

At a minimum, start taking your supplement 3 months before you get pregnant.

Continue taking this supplement throughout your pregnancy to help meet your

need for folic acid and other nutrients like iron.

• If you have had a pregnancy affected by a NTD or have a family history of this

problem, you should see your doctor. You may need to take a higher dose of folic

acid.

• If you have diabetes, obesity or epilepsy, you may be at higher risk of having a

baby with a NTD. See your doctor before planning a pregnancy.

• Do not take more than the 1 daily dose of a multivitamin. Do not increase your

dose of folic acid beyond 1000 mcg (1 mg) per day without talking to a doctor first.

RECOMMENDED FOLATE INTAKES FOR WOMEN OF CHILDBEARING AGE

Folate requirements have been set mainly based on the amount of dietary folate

equivalents (DFEs)

needed to maintain normal red blood cell concentrations (IOM,

(1) The term folate includes both natural folate found in food, and the synthetic form, folic acid, found in

fortified foods and vitamin supplements. The term dietary folate is used to describe all forms found in food:

natural folate, plus folic acid from fortified foods.

(2) The concept of dietary folate equivalents or DFEs for folate intake attempts to adjust for the

bioavailability of natural folate compared to folic acid, as natural folate is thought to be less bioavailable

(IOM, 1998).

1998). The Recommended Dietary Allowance (RDA)

for women of childbearing age is

400 mcg DFEs (IOM, 1998). In addition to dietary folate intake from a varied diet, all

women who can become pregnant should take a multivitamin

containing 400 mcg (0.4

mg) of folic acid every day. This reduces the risk of neural tube defects (Van Allen et al.,

2002).

RECOMMENDED FOLATE INTAKE DURING PREGNANCY

Folate requirements increase during pregnancy. There is a dramatic acceleration in cell

division and red blood cell development as the uterus enlarges, the placenta develops,

maternal blood volume expands, and the fetus grows (IOM, 1998). The mother also

transfers folate to the fetus (Antony, 2007). Evidence supports a RDA of 600 mcg DFEs

per day to maintain normal folate status during pregnancy (IOM, 1998).

NOT GETTING ENOUGH FOLATE

Because the body has a high demand for folate, women may not get enough of this

nutrient during their childbearing years (Power, 2005; Ortega et al, 2006; Sherwood et

al, 2006; Kirkpatrick and Tarsuk, 2008). Women who are at higher risk include those

who:

• are not taking the recommended folic acid supplement,

• are on restricted diets (such as chronic dieters),

• have a lower socio-economic status, and

• are experiencing food insecurity

HOW FOLATE HELPS PREVENT NEURAL TUBE DEFECTS

Neural tube defects (NTDs)

include spina bifida and anencephaly. They occur when the

neural tube fails to close properly during the third and fourth week of pregnancy. Often a

woman doesn’t yet know that she is pregnant during this critical time. A decreased risk

of NTD is associated with both increased folate intake and higher red blood cell folate

concentrations (greater than 906 nmol/L); though the experimental evidence is stronger

for increased folate intake and NTD risk reduction (IOM, 1998).

The risk is reduced when women start taking a daily multivitamin containing folic acid

three months before the beginning of pregnancy and continuing in early pregnancy while

the neural tube is closing (from 21 to 28 days after conception, or the 6

week after the

(3) The Recommended Dietary Allowance or RDA is the average daily dietary nutrient intake that is

sufficient to meet

the nutrient requirements of nearly all (97-98%) healthy individuals in a particular life

stage and gender group. The RDA for a nutrient can be used as a guide for daily intake (IOM, 2006).

(4) The term ‘multivitamin’ is used throughout this text as a short form for ‘multivitamin/multimineral

supplement’.

(5) Food insecurity refers to the limited or uncertain availability of nutritionally adequate and safe foods or

limited or uncertain ability to acquire acceptable foods in socially acceptable ways.

(6) For more information on the risk and development of NTDs, see Preconception health: folic acid for the

primary prevention of neural tube defects. A resource for health professionals

beginning of the last menstrual period)

(Van Allen et al, 2002). The reduced risk has

been observed in women who took a supplement containing 360 to 800 mcg of folic acid

per day, in addition to an intake of 200 to 300 mcg per day of natural folate (IOM, 1998).

Many studies also show that multivitamins containing folic acid taken in the early weeks

of pregnancy are associated with a decreased risk of oral cleft and cardiovascular

anomalies (IOM, 1998; Cziezel et al, 1999; Cziezel, 2004; Eichholzer et al, 2006; Goh et

al, 2006). Some evidence also suggests an association with reduced risk of

preeclampsia (Bodnar et al, 2006; Wen et al, 2008).

This is an area of active and on-

going research.

In light of this evidence, and recognizing that pregnancies are not always planned, the

Government of Canada has taken steps to help women of childbearing age increase the

amount of folate they consume through mandatory food fortification and the promotion of

vitamin supplementation for all women who could become pregnant.

REDUCING THE RISK OF NEURAL TUBE DEFECTS

MANDATORY FOOD FORTIFICATION

Adding folic acid to white flour, enriched pasta, and enriched corn meal has been

mandatory in Canada since November 1998. Studies show that this measure has

increased folate intake and improved folate status in Canadian women of childbearing

age (Ray et al, 2002; Liu et al, 2004). This population health approach has also been

associated with a significant reduction in the rate of NTDs. For example, a 7-province

study (from 1993 to 2002) showed a reduction of 46% in the overall rate of NTDs

post-

fortification (De Wals et al, 2007).

VITAMIN SUPPLEMENTATION FOR ALL WOMEN WHO COULD BECOME PREGNANT

Considering that the level of intake of folic acid from fortified foods is estimated to be no

more than 100 to 200 mcg per day,

and recognizing that many pregnancies are

unplanned, all women who could become pregnant should take a multivitamin containing

400 mcg (0.4 mg) of folic acid daily. This is in addition to the dietary folate provided by a

varied diet. Having women supplement their diets with folic acid between pregnancies

can help reduce the risk of NTDs in subsequent births.

Some women, such as those who have had a previous NTD affected pregnancy and

those with a near relative who has a NTD, are at higher risk of having a NTD-affected

pregnancy. They may need more than 400 mcg (0.4 mg) of folic acid daily (Van Allen

and McCourt, 2002). These women should be assessed early and advised on the steps

to take to prepare for a healthy pregnancy.

PROMOTING THE USE OF FOLIC ACID SUPPLEMENTATION

(7) This is a time when many women are not yet aware of their pregnancy.

(8) Data included births, stillbirths and cases detected prenatally that were subsequently terminated.

(9) These estimates are based on mandated levels of folic acid fortification (Canada Gazette part II, 1998).

According to Canadian survey data, 58% of women said they took a multivitamin

containing folic acid or a folic acid supplement in the three months before becoming

pregnant (Public Health Agency of Canada, 2009). It has been shown that the use of

supplements is influenced by economic status and educational background (Botto et al,

2005). For instance, the use of folic acid supplements before pregnancy in Canada was

lowest among women in lower-income households, among women with less than high

school graduation, and among immigrant mothers (Millar, 2004). Women with unplanned

pregnancies, mothers under the age of 25 and single mothers are also less likely to

supplement with folic acid (Ray et al, 2004).

Although the majority of Canadian women take folic acid supplements in the three

months before pregnancy, continued public health efforts are needed to promote

awareness of the importance of folic acid supplementation for all women of childbearing

age. To avoid increasing socio-economic inequalities in folic acid use, interventions

should provide practical support to vulnerable groups (Stockley and Lund, 2008).

CONTINUED SUPPLEMENTATION THROUGHOUT PREGNANCY

Canadian survey data show that it is difficult for most women of childbearing age to

consume enough folate from diet alone to meet their pregnancy needs. Over 75% of

non-pregnant/non-breastfeeding women aged 19 – 50 have intakes less than the

Estimated Average Requirement (EAR)

for pregnancy, 520 mcg of DFEs (Health

Canada, 2008). To meet folate needs during pregnancy, women should consume a

varied diet that provides dietary folate (see Table I), and continue taking a multivitamin

containing 400 mcg (0.4 mg) of folic acid throughout their pregnancy.

TABLE I SOURCES OF DIETARY FOLATE

Food 1 Food Guide

Serving

Micrograms

of folate as

dietary folate equivalents

(µg DFEs)

Lentils and romano beans 175 mL 265-270

Black beans 175 mL 190

Okra 125 mL 140

White beans 175 mL 125

Asparagus and spinach, cooked 125 mL 120

Salad greens, such as Romaine lettuce,

mustard greens and endive

250 mL 80-110

Pinto beans, kidney beans and chickpeas 175 mL 70-100

Pasta made with enriched wheat flour 125 mL 90

Avocado ½ fruit 80

Sunflower seeds, shelled 60 mL 80

Bagel made with enriched wheat flour ½ bagel (45 g) 60-75

(10) The Estimated Average Requirement or EAR is the average daily nutrient intake level that is estimated

to meet the requirements of half of the healthy individuals in a particular life stage and gender group. The

EAR is the primary reference point for assessing the adequacy of estimated nutrient intakes of groups; it is

the basis for calculating the RDA (IOM, 2006).

Food 1 Food Guide

Serving

Micrograms

of folate as

dietary folate equivalents

(µg DFEs)

Brussels sprouts, beets and broccoli,

cooked

125 mL 70

Bread made with enriched wheat flour or

enriched corn meal

1 slice or ½ pita

or ½ tortilla (35

45-65

Spinach, raw 250 mL 60

Orange juice from concentrate 125 mL 60

Parsley 125 mL 50

Parsnips 125 mL 50

Peanuts, shelled 60 mL 45

Eggs 2 large 45

Corn 125 mL 40

Seaweed 125 mL 40

Orange 1 medium 40

Green peas 125 mL 40

Raspberries, strawberries, blackberries 125 mL 15-35

Enriched ready to eat cereal 30 g 10-35

Broccoli and cauliflower, raw 125 mL 30

Snow peas 125 mL 30

Pineapple juice 125 mL 30

Walnuts, almonds and hazelnuts, shelled 60 mL 20-30

Baby carrots 125 mL 25

Kiwifruit 1 large 20

Clementine 1 fruit 20

a Amounts are approximate based on Canadian Nutrient File, 2007b.

IMPLICATIONS FOR PRACTICE

OPTIMIZING DIETARY FOLATE INTAKE

Following a healthy eating pattern and choosing foods that are rich in nutrients helps

women meet their requirement for folate and other nutrients. To promote adequate

dietary folate intake:

• Encourage women to use Canada's Food Guide

. It describes a healthy eating

pattern that is rich in dietary folate. Following Canada’s Food Guide will also help

women meet their needs for other nutrients and can help them achieve overall

health.

• Promote use of tools such as My Food Guide Servings Tracker

. This can help

women keep track of the amount and type of food they eat each day and compare

their intake to Canada’s Food Guide.

• Encourage women to include grain products fortified with folic acid each day, such as

enriched bread or enriched pasta

. They can make informed choices, by looking for

the term ‘folic acid’ in the ingredient list.

• Encourage women to have legumes, such as beans or lentils, often and eat at least

one dark green vegetable, such as peas or romaine lettuce, each day. (See Table I

for more dietary choices.)

• Refer women to a Registered Dietitian if they have a significantly restricted food

intake. This can happen when women exclude an entire food group or have severe

nausea or vomiting. These women can benefit from comprehensive nutritional

assessment and counselling.

• Refer nutritionally at-risk women to services or programs that can help. The Canada

Prenatal Nutrition Program

Website provides contact information for programs and

services for vulnerable pregnant women.

SELECTING A MULTIVITAMIN CONTAINING FOLIC ACID

For women who can become pregnant, health care professionals play an important role

in motivating them to use supplements (Eichholzer et al, 2006). To ensure proper use of

multivitamin supplements:

• Use the ‘Key messages on folate for women of childbearing age’ on page 1 to

write or talk about folic acid supplementation during the childbearing years.

• Encourage women to look for a multivitamin

that provides 400 mcg (0.4 mg) of

folic acid per daily dose. The product should also include vitamin B

• Advise women that prenatal supplements contain higher amounts of nutrients than

are usually needed by women who are not pregnant. A non-prenatal multivitamin

supplement is often enough. Following this advice can help women avoid taking

excessive amounts of nutrients over time.

• Ensure that women look for a Drug Identification Number (DIN) or Natural Product

Number (NPN) on the product label showing that the product is government-

approved for safety, efficacy, and quality.

• Emphasize the importance of reading product labels. Some supplements may

include cautionary notes about their use during pregnancy and breastfeeding.

• Caution women not to take more than one daily dose. This will help women not go

over the Tolerable Upper Intake Level (UL) for vitamin A

, which is 3,000 mcg

retinol activity equivalent (RAE) or 10,000 IU.

• Remind women to keep all supplements stored out of reach of young children.

(11) Some imported grain products, such as pasta, may not be enriched. Most rice is also not enriched.

(12) The Canada Prenatal Nutrition Program is developed and delivered in partnership with the provinces

and territories, and with First Nations and Inuit communities. The services provided include food

supplementations, nutritional counselling, breastfeeding support, education, referral and counselling on

health and lifestyle issues.

(13) Eligible First Nations and Inuit women of childbearing age can access multivitamins through the Non-

Insured Health Benefits Program (NIHB). For more information, please see www.hc-sc.gc.ca/fniah-

spnia/nihb-ssna/index-eng.php

(14) According to Health Canada’s Multi-vitamin/mineral supplement monograph, the vitamin A content per

daily dose must not exceed the UL for vitamin A.

ADVISING ON THE UPPER LIMITS OF FOLIC ACID SUPPLEMENTATION

High doses of folic acid can hide signs of vitamin B

deficiency. They can also bring on

or accelerate neurological complications associated with B

deficiency (IOM, 1998). As

well, women who have low vitamin B

status are at higher risk for NTD (Van Allen and

McCourt, 2002; Ray et al, 2007; Molloy et al, 2009). The prevalence of vitamin B

deficiency in women of childbearing age is considered very low (IOM, 1998). However,

some studies suggest that more women in this life stage group may have low vitamin B

status than expected (Ray et al, 2008). Women who do not or infrequently consume

foods of animal origin and do not take a vitamin B

containing supplement are most

likely to have deficient or marginal vitamin B

status (Allen, 2009).

Emerging data also suggest there may be additional health risks associated with taking

folic acid, including the development of colon cancer when preneoplastic cells are

present (Kim, 2006; Ashokkumar et al, 2007; Smith et al, 2008). It is important that

health care professionals do not advise higher doses of folic acid than is recommended

in this document, unless duly warranted.

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