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.
This is most likely to occur from taking supplements or high doses of cod liver oil. There is no danger of vitamin D toxicity from sun exposure. Symptoms of toxicity can be nausea, poor appetite, weakness, weight loss, constipation, and high blood levels of calcium. A blood level of over 200 ng/mL for vitamin D, measured as 25(OH)D, can be potentially toxic.