Wikipedia
Hematogen
Hematogen (, Gematogen; ) is a nutrition bar, which is notable in that one of its main ingredients is black food albumin taken from processed ( defibrinated) cow's blood. Other ingredients may vary, but usually they're sugar, milk, vanillin.
It is often considered to be a medicinal product, and is used to treat or prevent low blood levels of iron and vitamin B12 (e.g., for anemia or during pregnancy). Hematogen daily dose (50 grams for an adult) is able to provide the body with the necessary quantity of vitamin A.
It is available without prescription but in a case of pregnancy or breastfeeding a medical consultation is needed. Hematogen is not recommended for children under 3 years.