Modifiable behaviours during the first 1000 days of life influence developmental trajectories of adult chronic diseases. Recently, we reported on dietary intake and supplement use during pregnancy, including an examination of influential factors (Wilkinson et al. 2022; Gallo et al. 2024). The Queensland Family Cohort is a prospective, Australian observational longitudinal study (Borg et al. 2021). We observed poor alignment with Australian Guide to Healthy Eating recommendations for both pregnant people and their partners. Highest alignment was for fruit (40% pregnant) and meat/alternatives (38% partners) and lowest for breads/cereals (<1% pregnant) and milk/alternatives (13% partners). Pregnant people were more likely to meet daily recommendations for fruit, vegetables, dairy, bread/cereals, and meat/alternatives when their partners also met recommendations. Supplement use at 28 weeks’ pregnancy was reported by 89% of people, of whom 91% reported taking a multiple micronutrient (MMN) supplement. Pregnant people who received private obstetric care, had private health insurance, and had greater alignment to meat/vegetarian alternatives recommendations were more likely to report MMN supplement use. There was high reliance on supplements to meet guidelines for folate, iodine, and iron, but only plasma folate concentrations were higher in MMN supplement versus non-supplement users. More than 5% and almost 50% of those pregnant exceeded upper level of intakes for folic acid and iron, respectively. This was associated with higher plasma concentrations of the respective nutrients, and almost all were taking a MMN supplement. One in four pregnant people taking a MMN supplement also had very high intakes of iodine. Given low alignment with food group recommendations and potential risks associated with high MMN supplement use, wholefood diets should be emphasised. There is need to define effective strategies for optimising nutrient intake in pregnancy, including promotional strategies targeted at partners and for those most vulnerable where MMN supplement use may be appropriate.