An iron source product in form of solid capsules comprising a core comprising iron alginate, and an outer layer comprising calcium alginate. It is provided an iron source product in form of solid capsules, which is suitable both for fortifying hydrated and dehydrated food stuff, comprising a core comprising iron alginate, and an outer layer comprising calcium alginate. Additionally, it is provided a method for producing the mentioned iron source product, as well as an iron-fortified food stuff comprising an iron source product as defined above. The capsules defining the iron source product above are characterized by an excellent loading capacity, as well as having a good stability under standard local conditions of storage and use.