Good information about vitamins is hard to find, and there's a reason. With over 70% of Americans and 40% of Brits using them, it's a hugely lucrative market.
Cash incentives may explain the pro-vitamin argument. But what about those who think the vitamin supplement should be avoided? Can supplementing naturally occurring micronutrients really be dangerous?
Supplements markets lack regulation, especially in the US. No one really knows what's inside those pills they're popping.
Products containing many times the daily recommended doses are widely available. Could overdosing on these supplements actually lead to serious health complications?
Joanne Manson is a professor of epidemiology at the Harvard School of Public Health and one of the world's most cited researchers. Her achievements, spanning more than 40 years, are too many to list.
It's not essential if you have a healthy and balanced diet. And vitamins and mineral supplements will never be a substitute for a healthy diet.
Yes, it would be very reasonable to take 1,000 to 2,000 IUs a day.
A multivitamin may be worth seriously considering, just as a form of insurance and to hedge your bets. I would say second would be a vitamin D supplement, 1,000 to 2,000 IUs a day, a small to moderate dose, no mega dosing, not taking doses of 6,000, 10,000 IUs a day, but a small to moderate dose.
Vitamins are organic compounds or substances that our bodies usually do not make, but are essential for our metabolism and for good health. In fact, we do synthesize vitamin D through the skin when exposed to ultraviolet B light. But otherwise, vitamins and minerals are not made by the body. They're essential to function and we need to get them from food or from supplements.
Prof. JoAnn Manson emphasizes that most dietary supplements have not been well studied, and for many of them, there is very little research about efficacy or safety. She warns that many people are spending money on supplements that are not only of no value to their health but can be harmful, especially when taken in high doses.
She points out that for essential vitamins and minerals, there are guidelines provided by professional organizations, but for many dietary supplements, there are no appropriate dosage guidelines.
Prof. JoAnn Manson discusses her extensive research on various dietary supplements, including antioxidant vitamins, vitamin D, marine omega-3s, multivitamins, and cocoflavinol supplements. She highlights the lack of clear benefits for antioxidant vitamins and the potential risks associated with some of them. However, she mentions a significant reduction in total cancers and a 60% reduction in the rate of cognitive decline in the multivitamin group over three years.
Research on the value of taking it for shortening upper respiratory infection duration is controversial. Some studies show a little benefit, but for prevention of various diseases, it has not been shown to be beneficial in large scale trials. In fact, it might actually be harmful.
Vitamin E in the Physician's Health Study 2 showed increased risk of hemorrhagic stroke and higher all-cause mortality compared to placebo.
Avoid mega dosing of micronutrients and dietary supplements as they are not inert and can cause toxicity.
Look for recommended dietary allowance or daily intake on the label of dietary supplements and avoid exceeding it without clinician's supervision.
Check for quality control assessment seal on the label to avoid contamination and inaccurate dosing.
Excessive supplementation can burden the body and may not be necessary.
VITAL trial conducted on 25,000 U.S. men and women looked at vitamin D and omega-3 supplementation.
Prof. JoAnn Manson emphasizes the significance of the 25,000-participant study, highlighting the need for large-scale trials to assess clinical events.
The study found that vitamin D and omega-3s did not prevent major cardiovascular events, but there was a modest reduction in heart attack with omega-3s.
Vitamin D showed potential in reducing cancer death and advanced cancer, as well as autoimmune diseases.
Prof. Manson stresses the importance of a healthy diet as the primary source of vitamins and minerals, with supplements being a targeted approach for specific groups like pregnant women, infants, and older adults.
She advises against routine multivitamin use for children and emphasizes the need for professional guidance on supplement intake.
Prof. Manson highlights the safety and efficacy of specific supplements like vitamin D and multivitamins, cautioning against the use of untested dietary supplements.
Prof. JoAnn Manson has been covering a big area of research about everything to do with women's health.
Jonathan Wolff hopes to tempt Prof. JoAnn Manson back for a whole podcast just on the topic of women's health.
Dr. Sarah Berry thanked Jonathan Wolff for letting her gatecrash and expressed her pleasure in chatting with Joanne.
Jonathan Wolff thanks JoAnn Manson and Sarah for joining the podcast and encourages listeners to subscribe and leave a review.
He also invites listeners to send in their questions for future episodes and promotes Zoe's personalized nutrition program.
Listeners are directed to joinzoe.com/podcast for more information and a 10% discount on the program.