Choline is a chemical compound similar to and often included in the category of B vitamins. This nutrient is said to be important to the development of fetuses and infants, but is also thought to be beneficial in keeping the liver and cell membranes healthy in teenagers and adults. Although this substance is thought to be safe, too much of it can cause adverse reactions. Some of the most common choline side effects can include a pungent, fish-like body odor, diarrhea, and lowered blood pressure.
Though there is no official standard for how much choline should be taken on a daily basis, it is believed that most adults can tolerate up to 3,500 mg (or 3.5 grams) per day. Taking more than this amount can result in uncomfortable or potentially life threatening reactions. It is considered rare to develop certain side effects by consuming foods that contain this chemical; however, they can easily develop by taking too much in a supplement form. One of the most common side effects of over-supplementation is body odor. This odor is generally strong and may be similar to the scent of fish.
In addition to an unusual body odor, choline side effects due to taking too much of the supplement can result in excessive perspiration. This increase of perspiration may make the fish-like scent more noticeable, as the increase of moisture is a byproduct of the chemical being metabolized and excreted from the body. These symptoms can easily be remedied by lowering the dosage of the supplement or consuming fewer foods that contain choline.
Other common choline side effects are excessive salivation and stomach-related problems. Those taking this supplement or eating large portions of food that contain this chemical may develop an upset stomach, vomiting, and diarrhea. Additionally, some may experience a sudden lack of appetite.
Some people may develop allergic reactions or experience drug interactions, though such problems are uncommon. Allergy-related choline side effects can include a rash or hives, a swelling of the throat or tongue, and shortness of breath. Some prescription medications, including those for liver problems, neurological issues, and heart conditions, may negatively interact with this chemical, so it is important to speak with a physician prior to starting a choline supplement. Although more research needs to be done on the subject, some fear that another potential but uncommon side effect is an increased risk of colon cancer, especially in women.