Summary
This 46-page briefing paper from the British Nutrition Foundation reviewed the current state of maternal nutrition in the UK, from preconception through pregnancy, and found a widening gap between what women are advised to eat and what they're actually consuming. The nutrients most critical during pregnancy (iron, folate, iodine, vitamin D, and choline) are the same ones women of childbearing age are most consistently falling short on before they ever conceive.
The data is specific. 34% of women aged 19–65 have iron intakes below the Lower Reference Nutrient Intake. Iodine status has declined 25% in adult women and 29% in adolescent girls over the past decade. Only 19.7% of women in England were taking folic acid supplements before pregnancy in 2023–2024, down from 25.7% just four years earlier. Vitamin D insufficiency affects 17% of adult women and 26% of adolescent girls. These shortfalls are not the result of individual negligence. The paper frames them as a systemic failure of dietary guidance, food supply, and public health communication.
The paper also directly addresses the rise of plant-based diets during pregnancy. It notes that such dietary shifts must be "carefully managed" to ensure adequate intake of nutrients commonly sourced from animal products, specifically vitamin B12, iron, iodine, calcium, and long-chain fatty acids like DHA and EPA. These are not peripheral nutrients. They are among the exact ones the paper identifies as already insufficient in the general female population. DHA concentration in the fetal brain increases most rapidly during the third trimester, supporting neurological development and cognitive function. A meta-analysis of 26 randomized controlled trials cited in the paper found that omega-3 supplementation reduced preterm birth risk from 13.4% to 11.9% and low birthweight risk from 15.6% to 14.0%.
The review concludes that the updated standard of care should emphasize nutrient-dense whole foods, particularly those rich in iron, iodine, folate, calcium, vitamin D, and long-chain omega-3s, alongside targeted supplementation. The paper recommends folic acid supplementation beginning three months before conception (400µg/day), vitamin D supplementation (10µg/day) at minimum from October to March, and dietary patterns built around foods that deliver these nutrients in bioavailable form: meat, eggs, fish, and dairy.
PMID: 40618386
DOI: 10.1111/nbu.70016
Abstract
Pregnancy is a crucial period during which maternal nutrition, weight and lifestyle behaviours have a direct impact on both maternal and fetal health. This briefing paper describes dietary and lifestyle recommendations for women during the preconceptional period and throughout pregnancy, and considers key areas such as nutrient intakes, supplementation, food safety and weight management, highlighting how dietary choices can help reduce the risk of common pregnancy-related conditions. It draws together the findings of academic research and recommendations from authoritative institutions into a roadmap for good nutrition for parents and their babies. Despite widespread recognition of the importance of a healthy, balanced diet, many women in the UK fall short of recommended intakes for important nutrients, including iron, folate, iodine and vitamin D, with these shortfalls particularly evident among nutritionally vulnerable groups. The nutrients of particular concern are those for which there is an increased requirement during pregnancy including protein, vitamin A, thiamine, riboflavin, vitamin C, folate, iodine and choline. Diets should be based on the UK's healthy eating model, the Eatwell Guide, and include a variety of foods, with plenty of fruit and vegetables, starchy foods particularly wholegrain varieties, sources of protein such as beans, lentils, mycoprotein, nuts, eggs, fish and lean meat, low-fat dairy products and/or plant-based alternatives (fortified with calcium and iodine) and a small amount of unsaturated oils.