First foods

Some time between his fourth and seventh month your baby will get to the stage where he is ready for more than a liquid diet. He needs to be physically able to take in solid food. This means he must ave good head control (which usually happens between 16 and 20 weeks) and the tongue-thrust reflex must have disappeared. While baby still has this reflex,any solids put on his tongue will just come straight out again.
Baby also needs to be interested in food. If you sit him on your lap while you are eating he will soon let you know. Sometime he may seem as though he is not completely satisfied by his milk and be unsettled.
Begin by offering up to a spoon of a single food. This is very often rice cereal but can just as easily be banana or pureed stewed apple, pear, potato, pumpkin or carrot. Because both breast milk and infant formula contain all the nutrients your baby needs, your choice of food at this time is not nutritionally important. Don't offer fruit juice too early, however, as it can have a detrimental effect, replacing milk intake and causing diarrhoea.
After a day or two getting used to the first food, try another new food every two or three days until baby has sampled a range of foods andis eating three mini meals a day. If baby dislikes a particular taste, wait a few days and try again or mix it with a food he likes. 
Once he is around seven months old and accepting cereal and a variety of pureed vegetables and fruit, you can start him on other foods.
Your aim is to give your baby nutritious food and to educate him with healthy tastes, including water (boiled) as a drink.

Vitamin supplements

There is a growing concern amongst health professionals that we are raising a nation of pill-poppers by using vitamin supplements to safeguard our children's dietary intake. Babies and children do not need supplements if they are breastfed or formula-fed and eating a rangeof foods fromeach of the food groups once they begin family foods. If you are concerned about your child's nutrition ask your doctor before you add any. supplements to the diet. If you live in an area where the water is not fluoridated, ask your dentist about this supplement.
Remeber - too much of a nutrient can often be as harmful as too little.

Text source: Parenting Guides - Baby Food