I've never had stomach problems with any vitamins/supplements but I'm taking 2,000mg of Nordic Naturals DHA a day. I take them all at once in the morning. Two things come to mind. Try taking them with a lot of water, my ND recommended to drink a good amount of water for better digestion and better absorption. Second you might try a different brand, my ND specifically recommended the Nordic Naturals brand. My 2 cents.