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.
An overdose of vitamin A can cause serious or life-threatening side effects. Do not take vitamin A without medical advice if you are pregnant. Vitamin A can cause birth defects if taken in large doses. Before taking vitamin A, tell your doctor about all other medicines you use.