Unless you were directed by a doctor to use multivitamins or 'blood tonic', you are not supposed to give a baby of less than 6 months anything apart from breast milk. Practice exclusive breastfeeding for 6 months. All the nutrients the child needs for protection against infection and growth is contained in the breast milk. You can use a sterile cotton wool to gently clean the baby's tongue. Avoid teething powder for now unless the baby is irritable