INCLUSION CRITERIA FOR IRON PART:  Inclusión Criteria:  Healthy women aged 18-45 years Marginal levels of iron in blood as measured by serum ferritin <25ug/L. BMI: 18.5 to 25 kg/m2. Body weight <65kg. Prepared to attend study visits at the investigator site over a period of approximately 4 weeks (total 20 days) and, eat each day the prepared potatoes and then stay for a further 3 hours after eating the potato. Able to understand study requirements and provide written informed consent.  Exclusion criteria  Severe anaemia (Hb<80g/L) Evidence of inflammation as measured by C-reactive protein (CRP) (>5mg/100ml). Gastrointestinal or renal problems; self-reported metabolic disease based on prior diagnosis, or a prior screening questionnaire. Pregnancy (positive urine test). Currently breastfeeding. Currently taking any medication, antibiotic or supplement that might be expected to affect iron metabolism. Not willing to discontinue taking iron supplements for at least 2 weeks before taking part in the study. No significant blood loss in the last 6 months due to trauma, major surgery or blood donation. Not able to eat the full amount of the potato. Allergy to any ingredients of the test meal.  INCLUSION CRITERIA FOR ZINC PART:  Inclusion Criteria:  Healthy women aged 18-45 years. BMI 18.5-25 kg/m2. Willing to come to the study centre to eat the prepared potatoes on two occasions with a wash-out of 30 days (each day a different variety of potato) and to remain in the study centre for 7-8 hours in both occasions (one day to eat the biofortified variety and the other day the common variety) and as well to comply with all the study processes. Able to understand the consent form and to sign it.  Exclusion criteria  Severe anaemia (Hb<80g/dL adjusted for altitude). Inflammation measured as CRP (>5mg/100ml). Gastrointestinal, renal problems, metabolic illness (self-reported or prior diagnosis or evident from replies in a questionnaire). Pregnant (urine test). Breastfeeding. Taking medication, antibiotic or supplement that could affect zinc metabolism. Not willing to discontinue supplements for at least 2 weeks before participating in the study. Significant blood loss in the last 6 months due to trauma, surgery or blood donation. Unable to eat all the potato. Allergy to any ingredients of the test meal.