Thanks, great information!
Worst cases of everything from colds to cancers happen to people low on vitamin d3. A lot of adults in winter could really use 5000 IU s day. To know exactly precisely how much you need, you’d need and blood test now, start supplementing, then adjust dose after the next test in 2 months. Or you could just take 5000 IU now and worry a lot less about the sick kids visiting.