Supporting a Healthy Pregnancy: Nutrition, Weight & Supplements
What you eat, take as a supplement and your weight during pregnancy can influence both short- and long-term health outcomes for both you and your baby. Getting the right nutrition during pregnancy supports normal fetal growth and development. Having the correct amount of vitamins is associated with a reduced risk of neural tube defects, preterm birth, low birth weight, and later-life chronic disease.
This resource provides general, evidence-based nutrition information, however the guidance for nutrition and pregnancy can vary for different people depending on other health aspects. If you are pregnant or planning pregnancy, you should seek individualized guidance from your health care team including your dietitian.
Nutrition During Pregnancy
Most nutrient needs can be met by consuming a variety of whole foods across all food groups, including vegetables and fruit, whole grains, protein foods, milk or fortified alternatives, and healthy fats. Focus on eating a wide range of nutritious foods regularly, choosing good-quality options, rather than cutting foods out or following strict rules.
Energy (Calorie) Needs
Energy needs during pregnancy evolve over time and vary from person to person. Many individuals do not need intentional increases in intake during the first trimester. As pregnancy progresses, some may naturally require more energy to support growth and physiological changes, best guided by appetite, nutritional quality, and clinical monitoring rather than fixed calorie goals.
Key Nutrients During Pregnancy
While overall diet quality is most important, some nutrients need extra attention due to higher needs or common gaps. A prenatal multivitamin is recommended for most people during pregnancy. At a minimum, it should include folic acid, iron, vitamin D, and vitamin B12, though most contain additional nutrients to meet pregnancy needs. Your diet, health history, or lab results may require extra considerations, always check with your healthcare provider before adding any supplements.
The chart below shows key nutrients, why they matter, recommended daily amounts, and food sources.
| Nutrient | Why It Matters | Goal (from all sources, food + supplement) | Considerations | Food Sources |
|---|---|---|---|---|
| Folate/Folic Acid | Supports early fetal brain & spinal cord development; prevents neural tube defects | 600 mcg/day (400 mcg recommended from supplement) | Some may need more depending on health history or diet, ask your physician for guidance | Spinach, romaine, asparagus, broccoli, beans, lentils, avocado, enriched grains |
| Iron | Supports maternal blood volume expansion & fetal growth | 27 mg/day | Iron-deficiency anemia is common in pregnancy; especially for vegetarian/vegan diets | Red meat, poultry, fish, lentils, beans, tofu, fortified cereals |
| Calcium | Supports fetal bones & teeth; protects maternal bone health | 1,000 mg/day | Many meet needs via food; supplement if dairy-free or low intake | Milk, yogurt, cheese, fortified plant milks, tofu |
| Vitamin D | Supports bone health & immune function | 2,000 IU (50 mcg)/day | Sun exposure often insufficient; supplementation recommended | Fatty fish, fortified milk/plant milks, eggs |
| Vitamin B12 | Neurological development & red blood cell formation | 2.6 mcg/day | At risk if little or no animal products; supplementation often needed | Meat, poultry, fish, eggs, dairy, fortified plant milks |
| Iodine | Thyroid function & fetal brain development | 220 mcg/day | Usually sufficient in Canada; may be low if avoiding dairy, seafood, or iodized salt | Iodized salt, dairy, seafood, eggs |
| Choline | Fetal brain development & placental function | 450 mg/day | Not always in prenatal vitamins; dietary intake important | Eggs, meat (beef, chicken), soy, milk, fish (salmon), beans |
| Vitamin A | Supports growth & development | 770 mcg/day | Intake from supplements should not exceed recommended levels, and consumption of liver should be limited, particularly in the first trimester | Eggs, cheese, milk, yogurt, carrots, sweet potato, spinach, peppers, mango, papaya |
| Omega 3 (DHA & EPA) | Brain & eye development | 150 g (5 oz) cooked low-mercury fish/week | Doses of fish oil (EPA + DHA) of less than 3 g/day can be safely used by most individuals. Avoid fish liver oil supplements as they contain high levels of vitamin A. Look for an NPN when choosing a supplement | Fatty fish (salmon, sardines, trout), fortified eggs, fish oil supplements |
Weight & Weight Gain
Intentional weight loss is not recommended during pregnancy for anyone regardless of their weight. Weight loss during pregnancy puts you at increased risk of delivering a small for gestational age infant. The guidance to protect the health of both you and your baby is to follow a weekly rate of weight gain according to your pre-pregnancy BMI as shown in the chart below.
| Total Weight Gain | Rates of Weight Gain* 2nd and 3rd Trimester | |||
|---|---|---|---|---|
| Pre-pregnancy BMI | Range in kg | Range in lbs | Mean (range) in kg/week | Mean (range) in lbs/week |
| Underweight (< 18.5 kg/m²) | 12.5–18 | 28–40 | 0.51 (0.44–0.58) | 1 (1–1.3) |
| Normal weight (18.5-24.9 kg/m²) | 11.5–16 | 25–35 | 0.42 (0.35–0.50) | 1 (0.8–1) |
| Overweight (25.0-29.9 kg/m²) | 7–11.5 | 15–25 | 0.28 (0.23–0.33) | 0.6 (0.5–0.7) |
| Obesity (> 30.0 kg/m²) | 5–9 | 11–20 | 0.22 (0.17–0.27) | 0.5 (0.4–0.6) |
Source: Institute of Medicine and National Research Council 2009
Additional Considerations
Physical Activity: Unless you have been advised not to, most people are encouraged to accumulate at least 150 minutes of moderate-intensity physical activity per week during pregnancy. Exercise supports physical and mental health and has been shown to help manage pregnancy weight gain.
Medications: Certain medications, including GLP-1 receptor agonists, are not recommended during pregnancy or breastfeeding. If you are taking medications they should be reviewed with a healthcare provider before conception.
Food safety: During pregnancy, food safety is especially important to protect the developing baby from food-borne illnesses, which can cause serious complications. This includes avoiding unpasteurized dairy products, raw or undercooked fish and meats, and high-mercury fish, as well as following safe food-handling practices at home. For more information check out this link from Dietitians of Canada.
Drinks: Water is the best choice for staying hydrated during pregnancy and beyond. Caffeine should be limited to 300 mg or less per day (about one 12 oz cup of coffee) and is also found in tea, soda, and other beverages. Alcohol should be avoided completely, as even small amounts can harm fetal development. Energy drinks and herbal supplements are not recommended during pregnancy due to safety concerns and limited evidence of benefit.
Managing Common Pregnancy Symptoms
Nausea, vomiting, food aversions, and changes in appetite are common throughout pregnancy. Eating smaller, more frequent meals made of mild or slow scent foods may help manage symptoms. In cases of frequent vomiting speak to your doctor or nurse for additional support. Click the following links to learn more about managing low appetite, nausea and vomiting.
Supporting a Health Pregnancy
Pregnancy brings exciting changes and unique nutritional needs, and supporting your body with a balanced diet, appropriate supplements, safe activity, and regular healthcare follow-up can help both you and your baby thrive. If you’d like to learn more about nutrition during this time, speak to your Constant Health dietitian.
Resources:
https://obesitycanada.ca/wp-content/uploads/2025/03/18-Canadian-Adult-Obesity-CPG-Weight-Management-Over-the-Productive-Years.pdf
https://www.canada.ca/en/health-canada/services/food-nutrition/healthy-eating/healthy-weights/prenatal-guidelines-professionals-gestational-weight-gain.html
https://www.canada.ca/en/public-health/services/pregnancy/folic-acid.html
https://www.albertahealthservices.ca/assets/info/nutrition/if-nfs-ng-pregnancy.pdf
https://www.hamiltonhealthsciences.ca/wp-content/uploads/2019/08/VitaminDandPregnancy-trh.pdf
https://caringforkids.cps.ca/handouts/pregnancy-and-babies