Participants will be recruited within the University of Chester, UK only. Emails and posters/leaflets will be used as a medium of advertisement to the target group (staff and students). A total of 62 pre-menopausal women aged between 19 to 40 years old will be included in the study based on criteria described below. Eligibility will be based upon serum ferritin and also vitamin D concentrations at screening before the start of the study. Participants will be required to complete a screening questionnaire which will provide information about participant's health status, drugs/medication/supplement usage, and recent occurrences of illness/trauma/injury. A 6 ml venous blood will be drawn to assess concentrations of plasma ferritin vitamin D, haemoglobin and full blood counts, Participants with plasma ferritin concentrations below 20.0 µg/L and vitamin D concentration below 250 nmol/l will be included in the study. If the levels of haemoglobin are found to be in severe stage of anaemia, the potential participant will be notified and advised to consult their GP (haemoglobin levels < 8.0 g/dL). All eligible participants will be briefed on the study protocol before the beginning of the study, and the eligible participants will be given a Participant Information Sheet (PIS) and asked to provide written informed consent.