Parents commonly find giving medicines to babies, using oral syringes or spoons, difficult and emotionally stressful. In developing countries, additional stress arises due to hygiene difficulties and the lack of clean water. To overcome these challenges and encourage breastfeeding, we have developed the concept of a Therapeutic Nipple Shield, a delivery system that makes it possible to give medicine and nutrients to babies during breastfeeding. It consists of a silicone nipple shield that allows the release of medicine/nutrients into human milk during the feed. Presentations of a prototype to parents and staff at the Rosie Hospital was very positive, and encouraged this clinical study. This study aims to give a vitamin B12 supplement to babies during breastfeeding. The supplement will be placed into a nipple shield, both of which are commercially available, and the mother will breastfeed her baby as usual. Before and after the feed, we will 1) collect a small blood sample from the baby to see whether the vitamin levels in the infant have increased, 2) ask the mother to participate in two short interviews about her expectations and experiences using the Therapeutic Nipple Shield.

Inclusion Criteria:

No known allergy or hypersensitivity against any ingredient used in the study Infant aged up to 12 months Confident breastfeeder (exclusively or non-exclusively)

Exclusion Criteria:

The participant may not enter the study if ANY of the following apply:

• Not confident at breastfeeding
• Infant not feeding properly
• Allergy or hypersensitivity against any ingredient of the commercially available Methylcobalamin Vitamin B12 Tablets (Just Vitamins Ltd, UK) used in the study (infant or mother)
• Medical conditions that could negatively influence swallowing, and thus breastfeeding