ABC Online | Vitamin B3 'breakthrough' to prevent miscarriage claims premature, childbirth experts warn ABC Online Childbirth experts have issued a warning about research that has found vitamins can prevent many miscarriages in pregnant women. Key points: Medical experts say claims of B3 effectiveness in reducing miscarriage are potentially harmful; Royal ... Claims made about Vitamin B3 preventing miscarriages and birth defects are 'extraordinary' Pregnant? Vitamin B3 can prevent birth defects but don't take it yet Experts have urged pregnant women not to pin their hopes on niacin, Vitamin B3 |