Usually people ingest β-carotene in food and health food. The most important side effect of overdose of β-carotene is yellowing of the skin, and then there are no other clear side effects. Studies have pointed out that a daily intake of 20 mg/kg of β-carotene by smokers may increase the risk of lung cancer.
The main physiological effect of beta carotene on humans is to convert it into vitamin A. Excessive vitamin A supplementation can cause vitamin A poisoning. Therefore, the daily vitamin A intake of Chinese adults should not exceed 3000ug retinol active equivalent (unless under the guidance of a physician Treatment of vitamin A deficiency). But in fact, vitamin A poisoning is mostly seen in cases of large intake of vitamin A through drugs or dietary supplements. There are few cases of vitamin A poisoning caused by supplementation of beta carotene, because beta carotene needs to be decomposed by enzymes before it can be converted into Vitamin A, if you take in too much beta carotene, the enzyme will not be able to decompose it at all, and will not be converted into excessive vitamin A.
In any case, just make up the nutrients, don't overdo it. According to the recommended intake recommended by the Chinese Nutrition Society in 2013, adult men need 800ugRAE per day and adult women 700ugRAE per day. The conversion formula of β-carotene and RAE is: RAE=1/2*β-carotene in dietary supplements (health products)+1/12*β-carotene in food, the unit is ug.