I thought supplements were generally considered a scam, as our bodies won't/can't absorb vitamins in that form, we need to absorb them from food or sunlight.
It's fat-soluble so you're not as likely to just piss it out like the usual vitamins. D3 gets pretty good absorption. I wouldn't take it as a dry pill, if they even manufacture it like that. Get it in a liquid gel format that has it suspended in lipids. Take it with a meal or after.
If you really want to be anal about it, best move is to get your levels tested and then start supplementing and test levels again after a month, then up or down your dosage accordingly till you know how much you need to be taking daily. Most people depending on ethnicity, lifestyle/occupation, and locale just take like 500 - 5,000 IU D3 daily. If you're a white dude who goes surfing every day on the equator, you're probably good. If you're a black dude with a desk job, there's about a 90% chance you're deficient.
A doctor can diagnose extreme deficiency and might put you on like 50,000+ IU / week for a short while.
A lot of vitamins are water-soluble so they get flushed out fairly quickly if not immediately used. Vitamin D isn't such a vitamin and is stored in fat.
If you really want to be anal about it, best move is to get your levels tested and then start supplementing and test levels again after a month, then up or down your dosage accordingly till you know how much you need to be taking daily. Most people depending on ethnicity, lifestyle/occupation, and locale just take like 500 - 5,000 IU D3 daily. If you're a white dude who goes surfing every day on the equator, you're probably good. If you're a black dude with a desk job, there's about a 90% chance you're deficient.
A doctor can diagnose extreme deficiency and might put you on like 50,000+ IU / week for a short while.