When taken orally, doses of sodium bicarbonate higher than 0.3 grams per kilogram of body weight can increase the risk of gastrointestinal side effects, including bloating, nausea, and vomiting.[1][2]
Although some case studies of individual patients have found adverse effects of sodium bicarbonate, these are rare,[3][4][5] and, in general, sodium bicarbonate is considered safe for consumption when taken orally.[2][6]