Ensuring a healthy baby during pregnancy requires adequate nutrient intake. However, many people are relying on multivitamins, sometimes called “pink” multivitamins, instead of maintaining a healthy diet. These supplements are often marketed to those who are pregnant, breastfeeding, or planning to become pregnant and include a variety of nutrients such as folic acid, iodine, iron, vitamin D, vitamin B12, calcium, and more. Generally, multivitamins during pregnancy are not a worthwhile investment, and they may even pose a risk to you and your baby.
Official dietary guidelines suggest only two nutrient supplements are necessary before and during pregnancy: folic acid (folate) and iodine. A supplement of folic acid is advised starting a month before conception and continuing through the first three months of pregnancy at a dose of 400 micrograms daily to help prevent neural tube defects like spina bifida in the newborn. The need for folate remains significant throughout the entire pregnancy, and some individuals might require higher doses or different forms of folate based on their specific medical conditions. Due to mild iodine deficiency in Australia, individuals who are pregnant, breastfeeding, or considering pregnancy should take an iodine supplement of 150 micrograms daily to support the baby’s brain development. However, people with thyroid conditions should consult their doctor beforehand. Individual situations might necessitate additional nutrients during pregnancy.
For example, based on healthcare advice, people who follow a vegetarian or vegan diet may need vitamin B12 and iron supplements. Those with deficiencies like vitamin D or iron will receive a prescription to increase their levels. Individuals at risk of certain health issues, such as pre-eclampsia, might require a calcium supplement from the middle of their pregnancy. Multivitamins are commonly marketed as an important part of pregnancy care, and healthcare providers often recommend them. In Australia, research found that over 80 percent of people take multivitamins while pregnant, viewing them as a form of “insurance” to ensure sufficient nutrition. According to our study, using data from a Queensland group of pregnant families, socioeconomic factors influence multivitamin use during pregnancy. We discovered that individuals with private obstetric care, health insurance, and those who consume more meat—often associated with higher income—were more inclined to use them. This is not unexpected, given their high cost.
The most popular pregnancy multivitamin costs at least A$180 when taken from a month before conception and throughout pregnancy, compared to less than $40 for a supplement containing only folic acid and iodine for the same duration. Expensive brands are not necessarily better; their price is mainly determined by the public perception of brand quality, influenced by strong marketing campaigns. Excess vitamins are mostly expelled through urine, essentially making it costly urine. Our research found a heavy reliance on supplements, especially for folic acid, iron, and iodine, to meet nutrient requirements. If individuals’ diets already adequately provide these nutrients and supplements are adding more, there is a risk of nutritional overload.
For example, over one in 20 people in our study had excessive folate intake—exceeding the safe “upper limit.” Nearly half of participants exceeded the upper intake level for total iron. Nearly all of them were taking multivitamins and had unusually high blood levels of these nutrients. Consuming folic acid above the safe level may be linked to shorter birth lengths in babies, lower cognitive development in children, and a higher risk of childhood asthma. Folic acid supplementation, at the recommended daily dose of 400 micrograms after the first trimester, might benefit child cognitive development, but further studies are needed before it can be routinely recommended.
High iron doses can raise the risk of high red blood cell concentration in the expectant mother, which increases the likelihood of complications like having a small baby for gestational age, stillbirth, gestational diabetes, pre-eclampsia, and low birth weight. Regarding iodine, about one in four expectant mothers taking a multivitamin in our study had very high intakes, which have been associated with lower neurodevelopmental scores in children. In low- and middle-income countries, multivitamins play a significant role; they can improve weight gain during pregnancy and increase newborn weight while possibly reducing the risk of preterm birth. In high-income countries, like Australia, where food variety is abundant and mandatory fortification programs are in place (such as folic acid and iodized salt used in traditional breadmaking since 2009), frequent use of multivitamins can pose health risks to both mother and baby.
These risks include developing gestational diabetes—potentially due to high iron intake— and autism spectrum disorder in children. However, some individuals do not take any supplements during pregnancy. Our study, which examined supplement intake around 28 weeks of pregnancy, found that those under 30 years old and those from lower-income households were least likely to be taking supplements. These are also the groups typically having poorer diets. People should choose a supplement containing only folic acid and iodine at the recommended doses, or take these as separate supplements. They should work closely with their maternity care providers and possibly an accredited practicing dietitian to ensure they consume enough from all five food groups. Supplements should not be a replacement for a balanced diet. Eating a variety of foods offers benefits by providing many complementary nutrients and other compounds not found in supplements. Following dietary guidelines may also help save money.