Then come the more alarming ones. Excess vitamin D can lead to altered mental status, confusion, depression, and even psychosis in severe cases, with coma reported in extreme instances. Kidney damage, if left unchecked, can become permanent. It’s a cautionary tale that’s playing out globally as supplement culture outpaces medical guidance, wherein people are consuming Vit D supplements without medical supervision. The fix is straightforward, get tested before you supplement. A simple blood test tells you exactly where your levels stand. If you’re already supplementing, check every product you take, many combination vitamin supplements contain vitamin D, so the dose can add up faster than you’d expect. Vitamin D is genuinely important. But your body needs the right amount, not the largest bottle you can find.