Testing at five to six days. It is possible that instead of removing and testing one or two cells from a two â three day old embryo, some centres may allow the embryo to develop to five - six days, when there are 100-150 cells.
Long-term use of large amounts of vitamin A might cause serious side effects including fatigue, irritability, mental changes, anorexia, stomach discomfort, nausea, vomiting, mild fever, excessive sweating, and many other side effects.
The excessive ingestion of fat-soluble vitamins, such as vitamin A and D, and some water-soluble vitamins, including the various B vitamins and vitamin C, has the potential for serious side effects. Niacin may cause headaches.