<font color="0000ff">I've extracted the following about Unsupported claims about Vit C from the book entitled "Feed Your Child Right":</font>
The public has been exposed to a lot of publicity about the so-called benefits which may be derived from taking large doses of Vit C. It is popularly reputed to prevent the common cold, and many people take Vit C tablets in doses up to 100 times the recommended levels in the hope of fighting off colds and influenza.
These claims, however, are not warranted. There is no conclusive evidence that extra Vit C revents the onset of colds or shortens the duration of symptoms. In fact, taking high doses of Vit C over the long term has some deleterious effects on health. The higher the dose taken, the less Vit C is absorbed, and the unabsorbed Vit C passing through the digestive tract causes diarrhoea. Kidney and urinary tract stones are further risks related to high doses of Vit C. Large doses of the vitamin may also inactivate and destroy Vit B12 and interfere with the adsorption of Copper. On a more serious note, some studies have shown that large doses of Vit C taken in pregnancy may have adverse effects - harmful effects on the infant, who may get used to the high levels available to him in the womb and suffer Vit C deficiency (scurvy) temporarily after birth.
The conclusion from all of this is that Vit C should ideally be taken from dietary sources, and any self-medication with the vitamin is not advisable unless deemed necessary by a doctor.
<font color="0000ff">However, as well as protecting against anaemia by its assistance in iron absorption, Vit C is important in pregnancy as it promotes bone and ligament formation. Two portions of fresh fruit and two of vegetables daily will take care of the increased requirements during pregnancy.</font>