Do you think you can ever have too much face cream? Or is the more vitamins and minerals the better?
Think again: As our beauty routines become more complicated, we need to be careful not to inadvertently overdose on an ingredient or mix and combine products that could have dangerous consequences.
“We’re using way too many topicals and supplements,” says Dr Marvin Patterson, a beauty expert at Woodford Medical.
He warns that this can cause skin breakdown, interfere with medical tests and lead to serious health problems.
Read on to find out more…
Be careful with biotin
Biotin (vitamin B7) is a very popular vitamin that is widely used in hair, skin and nail supplements. It is water-soluble, so it does not accumulate in the body and there is no need to take large amounts. “Biotin is only useful as a supplement if you have a deficiency,” says nutritionist Emma Birdwell, who warns that taking too much can be dangerous, affecting both thyroid and heart tests.
Last year, the British Association of Generic Medicines Manufacturers wrote to healthcare professionals warning them that biotin could affect thyroid function results and that they should ask patients about their use of biotin and skin, nail and hair supplements before testing.
Surprisingly, biotin may also affect cardiac test results: In 2019, the FDA warned that high doses of biotin can significantly affect tests that measure troponin (a heart muscle protein released into the bloodstream during a heart attack), raising concerns that some tests could produce falsely high or low readings.
“When you go to hospital with chest pain, your troponin level will be measured,” says Dr Oliver Gutman, consultant cardiologist at Wellington Hospital, part of HCA Healthcare UK. “Biotin is sometimes used to check this level, so biotin supplements may affect the result. This is a concern as falsely low/negative troponin levels could lead to a heart attack being missed.”
Similarly, biotin is also used in thyroid tests, which can give false readings, Dr. Gutman says, and depending on the test used, it can produce falsely high or falsely low levels.
The NHS says that less than 0.9mg a day is not harmful, but in the lawless world of supplements, it’s easy to buy tablets containing as much as 12mg. The packaging recommends that you tell your doctor or pharmacist if you’re taking medication or have a medical condition, but we’ve been conditioned to consider supplements safe, so how many of us actually do this? Make sure you follow the advice.
Beware of Vitamin A
Hailed as a skincare miracle ingredient, retinol boosts collagen production, but in April this year the EU warned about overconsumption and implemented new legislation limiting the amount of retinol in products.
Experts warn that excessive use of retinol (applied as a cream or serum) can irritate and thin the skin.
“Although vitamin A from cosmetics represents a low proportion of overall consumer exposure, it may be of concern for consumers who have the highest vitamin A exposure from food and supplements (5% of the total population),” the Scientific Committee on Consumer Safety said.
“Too much retinol in the body can damage the liver and thin your bones, so it’s better to worry about skin irritation than systemic effects,” says Dr. Patterson, although he warns that using too much retinol alone can irritate and thin the skin.
The RDA for women in the UK is 600mcg (700mcg for men), but the NHS website recommends not exceeding 1500mcg in foods or supplements, and the Mayo Clinic warns that taking more than 3000mcg daily over the long term can cause the same problems as above, as well as joint and bone pain, headaches, nausea and diarrhoea.
Vitamin A is often marketed as a high-dose beauty supplement that’s cheap and easy to buy. In fact, taking one vitamin A tablet with a typical multivitamin (which provides more than 100% of your daily needs), eating some spinach and carrots, and using a topical cream containing retinol will give you a total of about 10,000 mcg.
…and too much vitamin C
“The recommended daily intake for adults is 40 mg, which is the minimum to prevent diseases like scurvy,” says Birdwell. “People tend to take very high doses of vitamin C to boost skin health and immunity. The upper limit is 2,000 mg a day, and even 1,000 mg can cause stomach issues like nausea, vomiting, and gastrointestinal discomfort.”
Taking this level of dose is easy, especially in powder form. “It’s unlikely to cause harm at high doses, but it could certainly cause discomfort if taken orally, and it could be very expensive as an IV.”
Do not mix and use
If you’re a fan of the TikTok trend of layering skincare products, be careful as mixing ingredients can be harmful.
“There’s only so much the skin can absorb, and mixing products can cause problems,” says Dr. Patterson. Applying retinol (or other forms of vitamin A) and vitamin C cream at the same time can overly dry out the skin, which can lead to irritation, as can vitamin C and AHAs, or retinol and salicylic acid applied at the same time.
Dr Patterson recommends avoiding using two products with the same active ingredient and “sticking to five basic products in the same range”.
Something seems fishy…
Ideally, we should get our omega-3s from oily fish, for example. Furthermore, supplements that claim to prevent dry or irritated skin or promote healthy hair and nails should be used with caution by those taking blood-thinning medications, for fear of increased bleeding risk.
Omega-3 supplements should be used with caution by people taking blood-thinning medications.
“Taking too many omega-3s can change how they are used by the body and make warfarin less effective.” [blood thinner] It’s more powerful,” Dr. Gutman said.
The British Heart Foundation recommends that if you take an omega-3 supplement, you should aim for around 450 mg per day (choose one that contains DHA and EPA omega-3s). Fish oil is known to thin the blood: in a study of 56 healthy adults who took 640 mg per day for a month, blood clotting was reduced.
“Everyone responds differently, but be sure to follow the recommended dosage and tell your doctor about any supplements you take,” says Dr. Gutman.
Lesser known side effects of taking large amounts of fish oil include heartburn and diarrhea.
