The safety of ferrous gluconate in food additives

As a commonly used food additive, the safety of ferrous gluconate is a matter of significant concern. Below is a re-evaluation of its safety:

Safety Basis

Ferrous gluconate has been recognized as a safe food additive by many countries and international organizations. For example, the U.S. Food and Drug Administration (FDA) classifies it as a Generally Recognized as Safe (GRAS) substance, and the European Union has approved its use as a food additive with the identification number E579. Additionally, according to China’s National Food Safety Standard for the Use of Food Nutritional Fortifiers (GB 14880-2012), ferrous gluconate can be used as a color retention agent and nutritional fortifier in foods—such as pickled vegetables (limited to olives)—with a maximum usage level of 0.15 g/kg. This also indicates that it is safe when used within the specified scope.

Toxicological Data

From a toxicological perspective, ferrous gluconate has high safety. The oral LD₅₀ (median lethal dose) in rats is 2237 mg/kg, classifying it as a low-toxicity substance. Furthermore, no ADI (Acceptable Daily Intake) value has been established for it, which means that based on existing data and usage conditions, there is no significant health risk under normal intake.

Impact on Human Health

Ferrous gluconate is an organic iron compound. Compared with inorganic iron supplements, it has higher bioavailability and causes less irritation to the gastrointestinal tract. At normal usage doses, it generally does not cause serious adverse reactions in the human body. However, excessive intake of ferrous gluconate may lead to some gastrointestinal discomfort symptoms, such as nausea, vomiting, diarrhea, and constipation. In addition, certain special populations—such as patients with hemochromatosis, severe liver disease, and those allergic to iron supplements—should avoid consuming foods containing ferrous gluconate to prevent adverse reactions.

Quality Standards

To ensure the safety of ferrous gluconate as a food additive, China has formulated corresponding quality standards, such as National Food Safety Standard for Food Nutritional Fortifier - Ferrous Gluconate (GB 1903.10-2015). This standard specifies requirements for sensory properties and physicochemical indicators, including the content of ferrous gluconate, loss on drying, content of ferric iron, reducing sugars, sulfates, lead, and total arsenic. As long as products comply with these quality standards, they are safe and reliable under normal use.