Alfacalcidol is a medication I've been taking to help regulate my calcium levels, but it's essential to be aware of its side effects. Some common ones include nausea, headaches, and dizziness. I've also heard that it can cause an increase in thirst and more frequent urination. It's important to monitor these symptoms and inform my doctor if they become severe or persistent. Lastly, I need to watch out for any signs of an allergic reaction like rash, itching, or difficulty breathing.