Dihydrotachysterol

 Risk Factor: A*
 Class: VITAMINS

Contents of this page:

Fetal Risk Summary
Breast Feeding Summary
References
Questions and Answers

Fetal Risk Summary

Dihydrotachysterol is a synthetic analogue of vitamin D. It is converted in the liver to 25-hydroxydihydrotachysterol, an active metabolite. See Vitamin D.

[*Risk Factor D if used in doses above the recommended daily allowance.]

Breast Feeding Summary

See Vitamin D.

Questions and Answers

Which one is vitamin D4: dihydrotachysterol or 22-dihydroergocalciferol?, Both based on wikipedia and I don't know if they are the same thing or not. If they are, please explain how to know that.

Vitamin D4 is synthesised in the body completely. It hence has many precursors and hence many names for these. In general calciferol tells you that it is related to vitamin D4, but to actually know what the substance is from name alone is difficult. The only way really is to view the structure of the compund and see if it relates to Vitamin D4.
I would advise you to use reliable sources for details and Wiki for just a genral picture.