Are there any side effects of including beet in my diet during pregnancy? Beet is an excellent source of folate and including beet in your pregnancy diet is a great decision. Beet aids in the crucial development of your baby’s spinal cord and prevents neural tube defects such as spina bifida. However, the presence of betaine and nitrate in beet might lead to mild side-effects like nausea, diarrhea, and gastrointestinal disturbances, so eat cautiously.