Investigating the effects of iron biofortification of microgreens in a vertical farm on iron status in women: Preliminary analysis of the VertiGreens study

This abstract was awarded the prize for best poster presentation. Women of reproductive age in the UK are particularly vulnerable to inadequate iron intake, with a substantial proportion of women consuming less than the recommended daily intake and experiencing iron deficiency (1,2) . Women are also more likely to reduce meat consumption or follow vegetarian diets (3) . Although these offer health and environmental benefits, they can be associated with lower iron content and reduced bioavailability (4) . While supplementation is an effective strategy to improve iron status, adherence is often poor, highlighting the need for sustainable food-based approaches (4) . Biofortification of plant foods offers a promising strategy to improve iron intake (5) and microgreens are particularly suitable due to their high nutrient density, rapid growth, and ease of dietary incorporation. This study examines the potential of iron-biofortified microgreens to improve iron intake and status. Healthy females who were not anaemic or taking iron supplements were recruited. In a within-subject study design, participants completed a week of recording habitual food intake, thereafter four continuous weeks of diet intervention. The intervention included consuming one smoothie per day containing the biofortified crops. When consumed in full, the smoothies provided 1.8 mg of iron per day. The microgreens were grown in a vertical farming system using a nutrient solution enhanced with iron. Iron status in participants was assessed from venous blood sampling on study day one and again on study day 28, to measure haemoglobin, serum iron status, ferritin, plasma CRP and serum Vit B12. Overall iron intake was measures using food diaries. The study is powered (n = 30) to detect within-subject effects (d = 0.53, 80% power). Preliminary paired t-test analysis is based on 13 of 30 participants. Preliminary data (n = 13) showed a significant mean increase in iron intake of 3.36 mg ± 1.90 (p < 0.001) during the intervention compared with habitual intake. Adherence was high, with 97% of smoothies consumed, and participants reported high enjoyment of the intervention. The average change in haemoglobin concentration over the intervention period was minimal and non-significant (p=0.49) at 0.012 g/dL ± 0.38, with considerable inter-individual variability. Haemoglobin is a relatively insensitive marker of short-term changes in iron intake. Increases in dietary iron intake are more likely to be reflected in serum ferritin concentrations, which indicate iron stores. This marker is still to be analysed. No significant gastrointestinal symptoms were reported, and participants did not experience changes in normal bowel habits, suggesting good tolerability of the intervention. Preliminary findings indicate that daily consumption of iron-biofortified microgreens is highly acceptable and increases dietary iron intake without adverse gastrointestinal effects. Further analysis of serum ferritin and other markers is required to fully assess the impact of this intervention on iron status.