As far as I know, low doses of beta-carotene (1,000–2,000 IU per day)
will not do too much harm. The best way to get vitamin D substrate,
as far as I can tell, is to take at least 5,000 IU of vitamin D3 per
day in the winter and stop all vitamin D in the summer and sunbathe.
Alternatively, use a tanning bed when the sun is too low on the
horizon to sunbathe. Remember, when you are outside, if your shadow
is longer than you are, you are not making any vitamin D.
La mayoría de los multivitamínicos traen vitamina A, en realidad casi
todos vienen sin las mejores fromas de las vitaminas y minerales.