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Alkaptonuria (AKU)


The ‘building blocks’ of protein are called amino acids. Alkaptonuria (AKU), also referred to as black bone disease, is a rare condition that results from the lack of an enzyme in the metabolic pathway of the amino acid tyrosine.


AKU is an inborn error of metabolism and is therefore present from birth. Until recently, only symptom management has been available for AKU, however, adults with AKU can now be treated with a drug called Nitisinone (NTBC).


A side effect of this drug treatment is an increase in the blood tyrosine level; where this exceeds the recommended range, this is referred to as tyrosinaemia. To manage this, a protein restriction is required to reduce the intake of tyrosine and phenylalanine* in the diet. In some cases, the low protein diet is combined with a protein substitute that is free from or low in tyrosine and phenylalanine. The protein substitute ensures an adequate protein intake, whilst keeping the blood tyrosine level within range. It also contains vitamins and minerals to meet a significant proportion of nutrient requirements where intakes from permitted foods are low.


Vitaflo® produces a range of age-specific, lifestyle-friendly and palatable protein substitutes for tyrosinaemia, whether as a result of hereditary tyrosinaemia or Nitisinone treatment in adults with AKU.


For further information please contact your local Vitaflo representative.


*Phenylalanine is a precursor to tyrosine.

Our product range for TYR



Inborn Errors of Metabolism 

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