While many sites consider shoyu to be safe for consumption during pregnancy, it can have negative effects on some pregnant women. Although shoyu is a good source of Riboflavin, Vitamin B6, Magnesium, and Copper, and highly rich in Protein, Niacin, Iron, Phosphorus, and Manganese, it is more of a condiment than a proper nutritional food. Usually, it is prepared from genetically modified ingredients, and even if it isn’t, it is full of artificial perservatives and often contains pesticide residue. Shoyu also contains glyphosate, a residue that can cause gestational diabetes and placental abnormalities in the mother, and birth defects in the baby. It is also high in phytic acid and trypsin – substances that inhibit the formation and absorption of essential minerals like calcium, magnesium, copper, iron, and zinc. However, if you still want to add shoyu to your diet, we recommend that you eat it in moderation and consult your doctor for further advice.