The present invention relates to dosage forms for oral administration of therapeutic formulations, adapted to provide immediate and/or sustained-release of therapeutic substances, particularly for oral administration of vitamins. There is provided a dosage form for oral administration of a vitamin, comprising: a liquid phase containing a vitamin, e.g. Vitamin C in a relatively fast release form and a solid phase suspended in the liquid phase and containing a vitamin e.g. Vitamin C in a relatively slow release form.