During pregnancy, you will need more of some vitamins and minerals than you would normally require. While the majority of these elements can be covered by eating a healthy and balanced diet, there are some which you need in exceptionally high amounts, and thus cannot be sourced from food alone. In particular, you'll need more folic acid, iron, and calcium.

According to the Cleveland Clinic, you should look for one that contains the following:

• 4,000 and 5,000 IU (international units) of vitamin A
• 800 and 1,000 mcg (1 mg) of folic acid
• 400 IU of vitamin D
• 200 to 300 mg of calcium
• 70 mg of vitamin C
• 1.5 mg of thiamine
• 1.6 mg of riboflavin
• 2.6 mg of pyridoxine
• 17 mg of niacinamide
• 2.2 mg of vitamin B-12
• 10 mg of vitamin E
• 15 mg of zinc
• 30 mg of iron

During my first pregnancy, I took prenatal vitamins - yes, the whole lot - during my whole pregnancy; however, this time around, with a different doctor, I was advised to stop taking any other multivitamins and was given a prescription for folic acid only. There are a myriad of prenatal vitamins available in the market. Ask your doctor or midwife for recommendations.