Dr. Arefa Cassoobhoy: I get a lot of questions about how safe the flu vaccine is when you’re pregnant. The answer is the flu shot is – very safe. It’s been given to millions of women over a long time and there’s no evidence of it being harmful. The flu vaccine is even safe for babies 6 months and older and is recommended for them. Does being sick lead to low vitamin D or does a low vitamin D level trigger other medical problems? OR, is something else completely different going on? While we wait for researchers to answer those questions, we do know this. Vitamin D is critical for strong, healthy bones throughout your life. Getting enough from the sun can be a challenge when you’re wearing sunscreen to protect your skin. And very few foods have vitamin D besides fortified milk, so it can be tough to rely on your diet to get vitamin D. For many people, a vitamin D supplement is a good idea. Check with your doctor to see how much you need to protect your bones. And for now, we’ll wait to see if taking vitamin D can help treat any other illnesses. For WebMD, I’m Dr. Arefa Cassoobhoy.