Supplements before pregnancy, and why more is not always better
Preparing for pregnancy can make the supplement aisle feel unexpectedly important. There are prenatal vitamins, fertility blends, hormone formulas, probiotics, antioxidants, herbal medicines and products claiming to support egg quality, sperm health, implantation or pregnancy.
People preparing for fertility treatment may be taking several of these at once, often after receiving advice from friends, online fertility groups, podcasts, social media or different health practitioners. Each recommendation may sound reasonable on its own. The difficulty is that products can overlap, interact with medications or provide much higher doses than intended when they are combined.
A useful supplement review is not about taking as many potentially beneficial nutrients as possible. It is about identifying what you need, removing unnecessary duplication and making sure that everything you take is safe alongside your medical and fertility treatment.
Supplements are not automatically harmless
Vitamins, minerals and herbal medicines are biologically active. That is why they may be useful, but it is also why they can cause side effects or interact with other treatments.
A product being described as natural does not mean it is appropriate before pregnancy. Some nutrients can be harmful at excessive doses, some herbs are not recommended during pregnancy, and many fertility supplements have not been adequately studied in people undergoing treatment.
There is also a practical problem with combining products. A prenatal multivitamin may already contain folic acid, iodine, iron, vitamin D and several B-group vitamins. If you add a fertility blend, a separate multivitamin, an iron supplement and a powdered wellness product, you may be taking the same nutrients three or four times without realising it.
This is why Nadia asks clients to bring a complete list of their current medicines and supplements—or photographs of the front and back of every product—to a preconception review.
Begin with the nutrients that have clear recommendations
A few nutrients have established roles in preconception and pregnancy care, although the appropriate dose can still vary according to the person.
Folic acid
Folic acid is recommended before pregnancy because it reduces the risk of neural tube defects, including spina bifida. Australian guidance generally recommends taking at least 0.5 mg daily for a minimum of one month before conception and during the first three months of pregnancy.
Some people are advised to take a higher dose because they have particular medical conditions, take certain medications or have a personal or family history that increases risk. A high-dose supplement should be recommended by a doctor rather than taken routinely “just in case.” RANZCOG planning for pregnancy guidance
Folate occurs naturally in foods, while folic acid is the form commonly used in supplements and food fortification. Eating folate-rich foods remains valuable, but food alone may not provide the amount recommended during the critical period before and early in pregnancy.
Iodine
Iodine supports thyroid function and the development of the baby’s brain and nervous system. Australian guidance generally recommends a daily supplement containing 150 micrograms of iodine for people planning pregnancy, during pregnancy and while breastfeeding.
People with thyroid disease should speak with their doctor before beginning an iodine supplement because their needs may differ. It is also important to add up the iodine contained across prenatal vitamins, thyroid products and other supplements rather than assuming each product can safely be taken together. NSW Health folate and iodine guidance
Not everyone needs the same prenatal vitamin
A prenatal supplement can be a convenient way to obtain recommended nutrients, but the product that suits one person may be unsuitable for another.
Factors that may change what you need include:
• A vegetarian or vegan diet
• Coeliac disease or another condition affecting nutrient absorption
• Previous bariatric surgery
• Heavy menstrual bleeding
• Anaemia or low iron stores
• Thyroid disease
• Diabetes or another metabolic condition
• PMOS, previously known as PCOS
• Kidney or liver disease
• A history of hyperemesis or significant gastrointestinal symptoms
• Multiple pregnancy
• Previous neural tube defect
• Prescription medication use
• A history of restrictive eating or an eating disorder
The aim is to choose a product that fills relevant nutritional gaps without providing unnecessary doses or worsening symptoms such as nausea, constipation or reflux.
Iron is important but more is not always better
Iron requirements increase during pregnancy, and low iron stores or anaemia should be identified and treated. However, taking iron when you do not need it can cause constipation, nausea, abdominal discomfort and other gastrointestinal symptoms.
The amount of iron in prenatal supplements varies considerably. Some people require additional iron based on their symptoms, diet and blood results. Others may already have adequate stores and find that a high-iron product makes them feel unwell.
Rather than choosing the supplement with the highest number on the label, discuss your history and recent blood results with your doctor. If iron treatment is needed, the dose, formulation and follow-up testing can then be matched to you.
Check the form and amount of vitamin A
Vitamin A is essential for health, but high doses of the retinol form can be harmful during pregnancy. This is one reason pregnancy supplements need to be chosen carefully.
Check whether a multivitamin, skin supplement, liver product or separate vitamin A supplement contains retinol or retinyl esters. Do not combine products containing vitamin A without professional advice.
Beta-carotene is treated differently because the body converts it to vitamin A according to need. Even so, the full supplement list should still be reviewed rather than assuming that a pregnancy label makes every combination safe.
Vitamin D and vitamin B12 depend on the person
Vitamin D is important for bone, muscle and immune health. Some people are at greater risk of deficiency because of limited sun exposure, darker skin, clothing practices, absorption problems or particular medical conditions. A blood test may be appropriate when there are clinical risk factors, but repeated testing and high-dose supplementation are not necessary for everyone.
Vitamin B12 deserves particular attention for people following a vegan or predominantly plant-based diet, those with absorption difficulties and people taking certain medications. If deficiency is suspected, it should be assessed and treated properly rather than relying on the modest amount contained in a general multivitamin.
Taking large doses without understanding the reason can complicate interpretation of later blood tests and may distract from an underlying medical issue that needs attention.
Be cautious about fertility blends and egg-quality claims
Many supplements marketed for fertility contain combinations of antioxidants, inositols, coenzyme Q10, herbs, amino acids and high-dose vitamins. Some individual ingredients have been studied in particular fertility populations, but this does not mean every blend is beneficial for every person.
Questions worth asking include:
• Was this ingredient studied in people with my diagnosis?
• Was it used at the same dose as this product?
• Was it studied during the type of fertility treatment I am having?
• Did the research measure a meaningful outcome, such as live birth, or only a laboratory marker?
• Is the evidence consistent across more than one study?
• Could it interact with my fertility medication or another health condition?
• Does my fertility clinic want me to stop it before egg collection, embryo transfer or surgery?
A product may affect hormones, blood glucose, blood pressure, bleeding risk, liver metabolism or sedation. Fertility clinics may also have specific instructions about supplements around procedures. Always give the clinic an accurate list.
The desire to improve egg quality is understandable, particularly when age, ovarian reserve or previous treatment outcomes are a concern. Unfortunately, supplements cannot reverse ovarian ageing, and no product can guarantee better-quality eggs or embryos. Careful supplementation may address a nutritional deficiency or form one part of a wider treatment plan, but it should not be sold as control over an uncertain outcome.
Men can also end up taking too much
Supplement marketing for sperm health often focuses on antioxidant formulas. Oxidative stress can affect sperm, but it does not follow that everyone providing sperm benefits from taking multiple antioxidants at high doses.
Men should also disclose prescription medicines, testosterone, anabolic steroids, herbal products, protein powders and gym supplements. Testosterone and anabolic steroids are particularly important because they can suppress sperm production and should be discussed with the prescribing doctor or fertility specialist.
Where a sperm-health supplement is being considered, the same principles apply: check the evidence, avoid duplication and make sure the product fits the person’s medical history and fertility plan.
Lifestyle and medical factors—including smoking, vaping, recreational drug use, alcohol, metabolic health, sleep and heat exposure—may be more important than adding another capsule.
Herbal medicines need specific review
Herbal products can interact with prescription medicines and may affect bleeding, blood pressure, blood glucose, liver enzymes, sedation or hormone activity. Safety information during pregnancy is limited for many herbs because pregnant people are rarely included in clinical trials.
A herbal medicine that was appropriate months earlier may no longer be suitable once fertility medication begins or pregnancy becomes possible. Some products may need to be stopped before a procedure or embryo transfer.
Do not rely only on the product name. Bring the full ingredient list and dose, as blends sold under similar names can contain very different substances.
Online products create additional uncertainty
Supplements purchased from overseas websites, social media sellers or unverified online marketplaces may not meet Australian standards. The ingredients or doses may differ from the label, and some products promoted as herbal or natural have been found to contain undeclared prescription substances.
Check whether a therapeutic product is included on the Australian Register of Therapeutic Goods and be cautious about products making dramatic fertility, hormone or weight-loss claims. Registration does not prove that a product will improve fertility, but it does provide an important level of regulatory oversight.
Supplements can also create emotional pressure
There is a psychological cost to being told that every nutrient, meal or biological process needs to be optimised.
People may spend hundreds of dollars each month, become anxious if they miss a dose or feel responsible when treatment is unsuccessful. Some continue taking products because stopping feels like giving up, even when the evidence is uncertain or the side effects are making them feel worse.
Fertility treatment already involves substantial uncertainty. A supplement plan should reduce confusion and support health, not create another demanding routine or suggest that treatment success depends on doing everything perfectly.
What to bring to a preconception supplement review
Before your appointment with Nadia, gather:
• All prescription medicines
• Over-the-counter medicines
• Prenatal vitamins and multivitamins
• Individual vitamins and minerals
• Herbal medicines and teas used therapeutically
• Fertility, hormone or antioxidant blends
• Protein, collagen, greens or meal-replacement powders
• Probiotics and microbiome products
• Sleep, energy, gym or weight-management products
• Any products used occasionally rather than every day
• Recent relevant blood results
• Instructions provided by your fertility clinic
Bring the original containers if possible. Otherwise, take clear photographs of the front label, ingredient panel, dose instructions and any practitioner-only label attached to the product.
It is also helpful to note why you started each supplement, who recommended it and whether you have noticed any benefit or side effects.
How Nadia approaches supplementation
Nadia reviews supplements within the wider context of your diet, medical history, symptoms, fertility treatment and current medications. She considers:
• Whether there is a clear reason for each product
• Whether the dose is appropriate
• Where ingredients are being duplicated
• Whether the product may interact with medication or treatment
• Whether blood testing or medical review is needed
• Whether the supplement is likely to provide meaningful benefit
• Whether a simpler or less expensive plan would meet the same need
• What should be discussed with your GP, fertility specialist or pharmacist
She works alongside your medical team and does not recommend stopping or changing prescription medication without the involvement of the prescriber.
Sometimes the result of a supplement review is adding something that is genuinely needed. Just as often, it involves simplifying the plan, changing the timing or formulation, or removing products that no longer have a clear purpose.
Good preconception care is not measured by the number of bottles on the kitchen bench. It is measured by whether your care is safe, relevant, nutritionally sound and coordinated with the treatment you are about to begin.
If you are preparing for pregnancy or fertility treatment, bring your current medicines and supplements to a preconception review with Nadia. To make an appointment, contact Lotus Health and Psychology on (07) 3132 8584.