Supplements are having a moment, and it is easy to see why. According to figures shared by the BBC, more than 74 percent of Americans and around two thirds of people in the UK reach for pills in hopes of boosting their health. The problem is that “natural” and “over the counter” can still come with real risks when doses creep higher and higher. This year, one American woman reportedly faced the threat of liver failure after taking too many turmeric tablets, a reminder that more is not always better. Neurologist Dr. Baibing Chen, known on TikTok as Dr. Bing, says three popular supplements deserve extra caution when taken in high amounts.
Vitamin D is often treated like a harmless winter essential, especially since the UK government advises many people to consider it during autumn and winter. It plays a key role in regulating calcium and phosphate, which support bones, teeth, and muscle function. But Dr. Bing warns that too much vitamin D can raise calcium levels in the blood, and that buildup can affect the brain. He says this may show up as confusion, fatigue, low mood, and in some cases even psychosis. For adults and children over one year old, the recommended daily amount is 10 micrograms, while babies under one need about 8.5 to 10 micrograms.
Vitamin A, also called retinol, is another nutrient that sounds straightforward until you look at how the body handles it. It supports immune function, helps vision in low light, and contributes to healthy skin and mucous membranes. Because it is fat soluble, Dr. Bing explains that it can be stored in the liver and gradually accumulate. In excess, he says it can trigger pseudotumor cerebri, which is increased pressure in the brain that mimics a brain tumor. That pressure can cause headaches, blurred vision, and in severe cases permanent vision loss.
@doctor.bing 3 supplements that can be toxic to your brain and nervous system if you take too much #brain #neurology #brainhealth #neurologist #supplements ♬ original sound – Dr. Bing, MD MPH
Dose guidance matters here because recommended intakes are not sky high. The UK’s NHS lists 700 micrograms a day for men aged 19 to 64, and 600 micrograms for women in the same age group. Dr. Bing also flags long term use above 1.5 milligrams, or 1500 micrograms, daily as a level that may weaken bones and raise fracture risk later in life. This is where stacking products can catch people off guard, since vitamin A may be in multivitamins, beauty blends, and specialty capsules at the same time. If you are pregnant or trying to conceive, vitamin A is also a nutrient that typically requires extra care and professional guidance.
Zinc rounds out Dr. Bing’s list because it hides in more products than many people realize. It supports cell production, enzyme activity, and wound healing, and it is found in multivitamins, lozenges, and some non prescription cold remedies. The issue, he says, is that taking zinc supplements daily for months can interfere with copper absorption. Copper is important for the nervous system, and low levels may lead to myeloneuropathy, damaging the spinal cord and peripheral nerves and causing numbness, tingling, and difficulty walking. Recommended daily amounts are 9.5 milligrams for men and 7 milligrams for women, and excessive zinc intake has also been linked to anemia and weaker bones.
Have you ever taken any of these supplements regularly, or reconsidered a dose after learning more about it? Share your experience and thoughts in the comments.
