I've run into this too. It's worth noting that there are a few different types of vitamin D. ergocalciferol - vitamin d2 derived from plants c

I've run into this too. It's worth noting that there are a few different types of vitamin D. ergocalciferol - vitamin d2 derived from plants cholecalciferol - vitamin d3 from sunlight - vitamin d3 derived from lanolin washed from lambs wool - vitamin d3 derived from lichen I've tried a few different types, many don't seem to make me feel any different. Liquid vitamin d3 [0] seems to work well at doses above 5k IU. [0] https://www.amazon.com/Designs-Health-Emulsi-D3-Emulsified-Vitamin/dp/B0039N3J58/ https://www.amazon.com/Designs-Health-Emulsi-D3-Emulsified-V...