Sam follow the guidelines per kind of fish as far as being a safe ammount to consume.
oomis 5000IU for an adult, and 2000IU for a child per day is not overdoining it. In general follow the directions on the Supplemented Bottle of D3. Do not exceed the recommended daily amount printed on the label of the bottle. Being that sunlight is a problem winter time (in the Northern Hemisphere) how is one going to get Skeletal Support unless they supplement? This is exactly why one has to Supplement with Vitamin D, Calcium and Magnesium and Omega Fish Oils following IU according to age of the one Supplenting. The other possibility is to eat foods that are a source of Vitamin D for additional support to the bones, immune system and more.
ronsr true about not getting enough sun light, that is why it is intelligent to Supplement with Vitamin D, Calcium and Magnesium, and Omega 3 Fish Oils to help support the Skeletal System. I also wrote when the Sun is shining to go outside and bask in the sunlight. I know one does not get 100% UV rays, because of the position of the sun in the sky wintertime, but even if one received 25-35% benefit it is better then no benefit. This would happen on a seasonably warm day. Being outside on a sunny day could boost your immune system that much more.