Vitamin B2 is one of the essential water-soluble vitamins for the human body, also known as riboflavin. It is closely related to human energy metabolism, and its deficiency can cause many diseases. Although China has a recommended daily intake for Vitamin B2, changes in dietary structure require a reassessment of its intake.
One vitamin, a body full of diseases
When the human body lacks Vitamin B2, early symptoms include fatigue, weakness, oral pain, and itchy eyes. Subsequently, oral and genital lesions appear, known as "orogenital syndrome," including cheilitis, angular stomatitis, glossitis, scrotal dermatitis, etc., seriously affecting people's normal life and work.
In recent years, research has shown that Vitamin B2 is also closely related to the function of the body's antioxidant defense system. Animal experiments have shown that Vitamin B2 malnutrition increases the activity coefficient of whole blood glutathione reductase, makes cells sensitive to oxidants and antibiotics, and also decreases the activity of the antioxidant superoxide dismutase in red blood cells.
For the elderly, Vitamin B2 malnutrition also shows a weakening of the body's antioxidant defense system. Some studies have shown that insufficient Vitamin B2 intake is also related to the occurrence of hyperhomocysteinemia, a risk factor for coronary heart disease. Supplementing with Vitamin B2 helps to reduce the concentration of homocysteine and blood pressure levels in the blood of specific populations.
Historical investigation of Vitamin B2 recommended intake
Wang Chengfa et al. in China once used the urinary load method to study the Vitamin B2 requirement of adult men in China. The results showed that after the daily Vitamin B2 intake exceeded 1.16 mg, the urinary excretion of Vitamin B2 increased significantly. Therefore, the Vitamin B2 requirement was set at 1.2 mg.
Several national nutrition surveys or monitoring data since the 1980s show that the average daily intake of Vitamin B2 for Chinese residents is 0.8~0.9 mg, which is only 61%~69% of the recommended daily intake for Chinese residents. The results of the "Evaluation of Nutrient Intake Status of Chinese Adult Residents" in 2012 showed that the proportion of macronutrient energy supply in the diet of Chinese adult residents is unreasonable, and the proportion of insufficient dietary Vitamin B2 intake exceeds 80%.
In this regard, some scholars believe that the previously established recommended daily intake of Vitamin B2 is too high, because according to the above surveys, the incidence of Vitamin B2 deficiency in Chinese residents should be high, but in reality, obvious deficiency is not common. Moreover, with changes in dietary structure, it will more or less affect the Vitamin B2 requirements of residents. Therefore, it is necessary to reassess the Vitamin B2 requirements of Chinese residents.
Recommendations for Vitamin B2 intake
Based on a review and analysis of previous related research, the team of Wei Jingyu, a senior experimental technician at the Institute of Hygiene and Environmental Medicine, studied a group of adult males in a centralized dining unit. They measured the concentration of free Vitamin B2 in the blood, combined with indicators such as dietary control and fasting urinary Vitamin B2 excretion, and finally made an analysis. They believe that the average requirement for Vitamin B2 for residents is 1.40 mg, which is consistent with the survey results of Wang Chengfa et al.