Some experts say that a fact is common knowledge if it can be found in three independent sources. Purdueâs Online Writing Lab recommends finding five independent sources before considering a fact common knowledge. The point is that common knowledge can be found in a variety of sources.
VITAMIN D. Vitamin D and vitamin A are the most toxic of the fat-soluble vitamins. The symptoms of vitamin D toxicity are nausea, vomiting, pain in the joints, and loss of appetite. The patient may experience constipation alternating with diarrhea, or have tingling sensations in the mouth.
Excess of some vitamins, especially fat-soluble vitamins such as vitamin A, can be toxic. Vitamins are classified as either water-soluble or fat-soluble. In humans there are 13 vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C).