There are many nutients in dandelions including vitamins A,B1, B2, B3 C and E and minerals such as calcium , copper iron, magnesium and phosphorus. They contain more beta carotene than carrots, more potassium than bananas, more iron than spinach and more lecithin than soyabeans. Therefore despite its bitter taste dandelion is packed with nutrients.
The scientific name for dandelion Taraxacum officinale translates as an official remedy for disorders. The information is given here for interest. I have not tried these remedies or tested their efficacy or side effects and I am not recommending them. However, I have found them freely available on the internet or in books.
Culpapers herbal describes it as follows
“It is under the dominion of Jupiter. It is of an opening and cleansing quality, and therefore very effectual for the obstructions of the liver, gall and spleen, and the diseases that arise from them, as the jaundice and hypocondriac; it opens the passages of the urine both in young and old; powerfully cleanses imposthumes and inward ulcers in the urinary passage, and by its drying and temperate quality doth afterwards heal them; for which purpose the decoction of the roots or leaves in white wine, or the leaves chopped as pot-herbs, with a few Alisanders, and boiled in their broth, are very effectual. And whoever is drawing towards a consumption or an evil disposition of the whole body, called Cachexia, by the use hereof for some time together, shall find a wonderful help. It helps also to procure rest and sleep to bodies distempered by the heat of ague fits, or other wise. The distilled water is effectual to drink in pestilential fevers, and to wash the sores.
You see here what virtues this common herb hath, and that is the reason the French and Dutch so often eat them in the Spring; and now if you look a little farther, you may see plainly without a pair of spectacles, that foreign physicians are not so selfish as ours are, but more communicative of the virtues of plants to people.”
Traditionally Dandelion greens applied as a poultice were used to treat breast cancer
The potassium present in the leaves provides dandelion with its diuretic properties. These diuretic properties have resulted in its use to ‘cleanse’ the kidneys and aid kidney stones.
The bitter compounds in the leaves and root are reputed to stimulate digestion leaves by increasing bile production in the gall bladder and are mild laxatives. In France, dandelion flower buds are sometimes served with pickled beetroot as an apperatif. The increase in bile production which is stimulated by dandelions has led to its use in the treatment of liver complaints.
As so many compounds are present in dandelions the interaction of the various constituents may provide the beneficial properties rather than any one chemical.
The flowers have been used as a poultice for cuts and the latex like sap from the stalk was traditionally used to treat warts although there is some evidence that it can cause contact dematitis in susceptible individuals.
In summary the plant has been used for hundreds of years to treat a variety of disorders both internally and externally.