I recently asked our clients if they consult a Doctor before starting supplements. The majority replied NO.

As a medical doctor I always check what supplements my patients are taking in addition to their regular medications. Why? Because not all supplements are safe.

Many people take supplements almost every day. We all know that vitamins are essential for life, and vitamin deficiencies can definitely be harmful. There is an abundance of readily available dietary supplements and vitamins in the present market, available over the internet and in supermarkets and pharmacies. It is a common belief that vitamins are an inexpensive way to supplement a poor diet, address any deficiencies and get healthier. Most of us, however, don’t consult a health care professional before deciding to take them based on the limited information available on the internet.

I have listed a few commonly used supplements which can be harmful to your health.

Vitamin A and beta carotene – Antioxidants (Vitamin A, C, E) are being widely promoted for their anti-cancer properties. Vitamin A is vital for good vision, but too much Vitamin A (in the form of supplements) can be toxic. A large study (ATBC in 2014) concluded that although Vitamin A slightly reduced the risk of prostate cancer in men , it increased the risk of lung cancer in smokers. Vitamin A taken by pregnant women is also known from studies to be linked to birth defects.

Vitamin B – Commonly referred to as the anti-ageing vitamin, Nicotinamide Riboside a variant of Vitamin B3 from recent research (Goun et al 2022) has been shown taken in high quantities to increase the risk of brain cancer, breast cancer and brain metastasis. High levels of Vitamin B6 have also been linked to some types of nerve damage.

Vitamin C – Linus Pauling, published a book in 1970 recommending high doses of vitamin C to prevent the common cold. Although Pauling was an intelligent chemist and also a Nobel laureate, he was indeed wrong about Vitamin C and its role in the prevention of colds. A large research review (Douglas et al 2005) proved that Vitamin C doesn’t prevent or cure colds. In fact, in high doses, it can increase the risk of kidney stones.

Vitamin D – Very high doses of vitamin D can cause increased calcium (hypercalcemia) which can lead to dehydration, kidney damage and seizures.

Vitamin E – Another popular supplemental vitamin, Vitamin E, has been found to increase the risk of prostate cancer in men (Klein et al 2011) and another study by John Hopkins Institute (Miller et al 2005) showed that supplemental “Vitamin E in excess of 400 IU (international units) consumed daily, was associated with an increased risk of dying”

Calcium supplements- Research proves that people who take calcium supplements are at higher risk of depositing calcium in their arteries which can lead to atherosclerosis and increased risk of heart attacks (Anderson et 2016). Dietary calcium intake is safe. The target calcium intake from dietary sources and supplements should be 1000 mg per day for adults, rising to 1300 mg per day for women older than 50 years of age and men older than 70 years of age.

St. John’s Wort – This popular supplement to treat perimenopausal symptoms interacts with many medications and should be taken with care after approval by your medical Doctor.

Multivitamins – Multiple studies have proven that multivitamin supplements are not effective and shouldn’t be replaced by a healthy diet. “In older women, several commonly used dietary vitamin and mineral supplements may be associated with an increased risk of death; this association is strongest with supplemental iron (Mursu et al 2011)

Fish oil – rich in omega-3 fatty acids, and has been promoted as a means to reduce heart disease and other medical issues. But increasing evidence proves that fish oil supplements have questionable benefits. Fish oil acts as a blood thinner and can increase the risk of bruising and bleeding especially following medical procedures. A recent study (Manson et 2019) found that omega-3 supplements do not reduce the risk of heart attacks, strokes, or deaths from heart disease in middle-aged and older men and women without any known risk factors for cardiovascular disease. Research evidence also proves that Omega 3/6 has little or no effect on the prevention of type 2 Diabetes (BMJ 2019)

Kava – Commonly used to relieve symptoms of anxiety, this supplement when taken in increased doses can damage the liver leading to cirrhosis.

So after studying all the evidence, supplementing your diet with vitamins has almost no benefit, but instead, can be harmful. These supplements don’t improve your immune system, don’t reduce stress, don’t help prevent colds or other infections and have no impact on joint health.

My medical advice is to focus on a healthy and balanced diet rich in all necessary nutrients which supports a healthy gut microbiome. Also add 10-15 minutes of safe sun exposure per day to top up your vitamin D.

Please ignore the flashy marketing strategies of the manufacturers of these products and check with your doctor before starting any supplements from over the counter.

Stay Healthy!