Vitamin A
Deficiency and Toxicity
- Deficiency Symptoms
Mild deficiency may cause night blindness, dry skin, and increased susceptibility to infections. Severe, long-term deficiency can lead to xerophthalmia (dry eyes progressing to corneal ulceration and blindness), growth retardation in children, and impaired reproductive function. Deficiency is more common in regions with limited access to animal products and diverse fruits/vegetables.
- Toxicity
Unlike water-soluble vitamins, excess vitamin A accumulates in the liver, leading to hypervitaminosis A. Acute toxicity (from very high doses in a short time) can cause nausea, vomiting, headache, and blurred vision. Chronic toxicity (from long-term high-dose supplementation) may result in bone pain, hair loss, liver damage, and birth defects in pregnant women. Provitamin A carotenoids have low toxicity risk, as the body limits their conversion to retinol; excess intake may only cause harmless skin discoloration (carotenemia).
Recommended Intake
| Company Name | Reman (ShangHai) Bio-tech-Co.,LTD | Country/Region | China |
| Business Type | Trading Company | Company Size | 2 |
| Established | May 4, 2018 | ||
| Address | 嘉定区江桥镇鹤旋路26弄万达9号写字楼810室 | ||
| Main Products | Lehman (Shanghai) Biotechnology Co., Ltd. was established on May 4, 2018, with its registered address at Room J1078, 1_203, No. 337 Shahe Road, Jiangqiao Town, Jiading District, Shanghai. The legal representative is Zhang Huaqiang. The company's business scope includes technology development, technology transfer, technology consulting, and technical services in the fields of biotechnology, new energy technology, environmental protection technology, and agricultural technology. It also engages in the sales o | ||
Lehman (Shanghai) Biotechnology Co., Ltd. was established on May 4, 2018, with its registered address at Room J1078, 1_203, No. 337 Shahe Road, Jiangqiao Town, Jiading District, Shanghai. The legal representative is Zhang Huaqiang. The business scope includes technology development, transfer, consultation, and services in the fields of biotechnology, new energy technology, environmental protection technology, and agricultural technology; sales of laboratory equipment, chemical raw materials and products (excluding hazardous chemicals, monitored chemicals, fireworks, civil explosives, precursor chemicals), pet supplies, pet feed, feed additives, and food additives; and import and export of goods and technology. [Projects subject to approval according to law must be approved by relevant departments before business activities can be conducted.]