Actually, he recently recommended 8,000 iu of vitamin D3, so if you take at least the 5,000 iu, you can't overdose on that much. Not even as a senior. In
we just don't have any sun exposure, because what sun is available won't help because it's much too cold to have sufficient skin exposed to the sun. If you take a medication for acid reflux to deal with the burning from the H. Pylori, such medication is known to cause malabsorption and to cause vitamin D deficiency.