If you're out in the sun every day, probably not. If you are indoors all day, it's probably a good idea to take a supplement. This calculator page is a great wa

If you're out in the sun every day, probably not. If you are indoors all day, it's probably a good idea to take a supplement. This calculator page is a great way to estimate how much time outside it would take for you to get generate a specific level of vitamin D given your skin colour, latitude, cloud conditions, time of day and so on: https://fastrt.nilu.no/VitD-ez_quartMEDandMED_v2.html https://fastrt.nilu.no/VitD-ez_quartMEDandMED_v2.html For me it calculates only 15mins needed in the sun to get an equivalent dose of 1000IU. Note however that depending on where you read, a recommended dose per day may be 10,000-15,000IU.