Extremely safe and free of excess symptom

Vitamin C is exceptionally safe. 100g of it could cause diarrhea, but no acute symptoms of its toxicity. With reference to the tens of millions of people who are continuously taking several grams of vitamin C supplement, no cases of adverse effects that are considered as chronic intoxication are reported. It is not teratogenic, mutagenic, genotoxic, or carcinogenic. Vitamin C is safe for the reason that it is a water-soluble vitamin and a biological material.

Minor side effect such as diarrhea

Taking vitamin C may cause diarrhea on rare occasions due to its laxative effect. Looseness of the bowels usually occurs if 2g or more of it is taken when hungry. Ascorbic acid is the chemical name for vitamin C. It functions as an acid and triggers peristalsis in the intestine. Fortunately, this is just a benign transient diarrhea and not something to be concerned about. As it can cause loosening of the stool on an empty stomach, the right timing to take vitamin C is after meal that is when you are full. Package inserts of over-the-counter vitamin C supplements indicate “nausea and vomiting in rare case”, but this will not occur if only several grams of it are taken after a meal a day.

Unwarranted side effects

After 1970, people taking vitamin C have increased thanks to Dr. Pauling. Following it, rumors and scare stories about the side effects of it have spread, such as developing calcium oxalates stones due to the increase in urine oxalic acid level, and making urine and blood acidic. However, studies have been made based on these rumors and all are refuted. People never have to worry in taking vitamin C as it has no risky compound.

May affect clinical examination

It has no side effect but the more vitamin C you take, the more you excrete it through urine that results in higher level of vitamin C in it. When there is more than 12mg in 100g, vitamin C in urine becomes detectable. In particular, a urine glucose test done with test strips seems to easily detect the vitamin C level. In Western countries, where vitamin C is widely used, they use a urine test that is not affected by vitamin C. However, this way of testing is not yet practically used in Japan. Because of this, it is recommended not to take vitamin C for 2 to 3 days before the urine test. Not taking vitamin C for a while will lower the levels of it in the urine. Vitamin C does not affect blood tests at all. Even if you take a huge amount of it, there will not be over 3mg in 100 ml of it in the blood.