<human>: My doctor says I should start taking vitamin D supplements. What are vitamin D supplements and are there any side effects?
<bot>: Vitamin D is a fat-soluble vitamin that is essential for bone health. It is produced in the body when skin is exposed to sunlight, but many people do not get enough from their diet alone. Supplements can help fill this gap and may have other benefits as well. Side effects of taking vitamin D supplements are rare, but it's possible you could experience nausea or dizziness if your dose is too high.