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Supplements are hot right now, with celebrities from Venus Williams and LeBron James to Arnold Schwarzenegger launching products into a global supplement market estimated to be worth $177.50 billion in 2023.
That's despite many dietitians recommending we get our nutrients from a healthy diet, with some believing supplements are a waste of money.
Dr. Zalan Alam, a family doctor in the UK, who specializes in improving the quality of life of older people, told Business Insider that research on supplements can be contradictory and confusing, making it hard to decide whether to take supplements.
"It's all about personalization," he said. "It depends on your biological age and what you're looking to target."
He recommended speaking to a medical professional about your health issues and priorities, and to ensure supplements don't interfere with your medication.
Alam takes three supplements to address his own health priorities, which he shared with BI.
Alam drinks coffee containing lion's mane mushroom extract each morning. Lion's mane is an adaptogen, which is a plant substance that research suggests might help balance out the chemical reactions in the body and reduce stress, according to the Cleveland Clinic. However, the research is still quite limited.
Alam started taking lion's mane to help him cut down on coffee. Although coffee does have health benefits, he was experiencing caffeine crashes and wanted to avoid the heart palpitations and increased blood pressure that can arise from drinking too much.
Since he started having the lion's mane/coffee blend, he drinks far fewer cups each day, has noticed fewer energy crashes, and feels less sluggish throughout the day, he said.
Whether this is down to the lion's mane is unclear — there isn't much research on the impact of the mushroom on energy levels or sluggishness. However, a 2024 review of studies published in the journal Neuroscience and Biobehavioral Reviews found that lion's mane and other mushrooms could reduce anxiety, improve mood, and improve cognitive functioning. The researchers noted that more research needs to be done to confirm these findings.
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Alam takes zinc in the hope it might make him less sick when he's exposed to bugs from patients.
"Zinc doesn't stop you from picking up a bug, but it does reduce how bad the bug or the infection could be when you do get it. So it might reduce the length of time that you're feeling unwell, or it might reduce the delays in your recovery," he said.
A 2022 review of studies published in the journal Nutrients found zinc appeared to shorten the duration of colds and lessen symptoms, but more research is needed.
Most people in the US get enough zinc from their diets, according to the Office of Dietary Supplements, but Alam thinks taking zinc supplements is "worth a try" because most doses of zinc from shop-bought supplements "aren't going to cause any harm."
It's important to note, though, that taking too much zinc (more than 40 milligrams a day for adults) can lead to nausea, dizziness, headaches, an upset stomach, vomiting, and loss of appetite, according to the Office of Dietary Supplements.
From September to whenever the weather improves in the spring, Alam also supplements his diet with vitamin D, which is necessary for bone health, calcium absorption in the gut, reducing inflammation, and immune function, according to the US Office of Dietary Supplements.
"Research says if you were to test every person in the UK at the end of a long winter, probably 40% of us would be vitamin D deficient. Especially with our lifestyles nowadays as we're more indoors," he said. In the US, about 35% of adults have vitamin D deficiency, according to Cleveland Clinic.
Guidelines on supplementation are different around the world. For example, the UK government advises people to consider taking vitamin D during the fall and winter, whereas The Endocrine Society doesn't recommend vitamin D supplementation for healthy adults aged 19 to 74, because research doesn't suggest a clear amount which is effective for preventing disease.
It's up to the individual to decide whether to take vitamin D supplements, but, like zinc, they are unlikely to cause harm when taken in safe amounts, Alam said.
