vitamin
Norbert Hofer is the former leader of the Austrian right-wing FPÖ party who almost became Austria’s President. Currently, he is the 3rd member of the National Council. Hofer is a man full of surprises; he stated, for instance, that the Quran was more dangerous than COVID-19 during a speech held at a 2020 campaign event. As a result, he was sued for hate-speech.
Hofer’s latest coup is not political but commercial: Hofer is launching his own dietary supplement on the market. It is called “Formula Fortuna” and contains:
- L-tryptophan; a Cochrane review concluded that “a large number of studies appear to address the research questions, but few are of sufficient quality to be reliable. Available evidence does suggest these substances are better than placebo at alleviating depression. Further studies are needed to evaluate the efficacy and safety of 5‐HTP and tryptophan before their widespread use can be recommended. The possible association between these substances and the potentially fatal Eosinophilia‐Myalgia Syndrome has not been elucidated. Because alternative antidepressants exist which have been proven to be effective and safe the clinical usefulness of 5‐HTP and tryptophan is limited at present.”
- Hydroxypropylmethylcellulose, a common delivery system.
- Rhodiola rosea extracts; human studies evaluating R. rosea did not have sufficient quality to determine whether it has properties affecting fatigue or any other condition.The U.S. Food and Drug Administration (FDA) has issued warning letters to manufacturers of R. rosea dietary supplement products unapproved as new drugs, adulterated, misbranded and in federal violation for not having proof of safety or efficacy for the advertised conditions of alleviating Raynaud syndrome, altitude sickness, depression or cancer.
- Ginseng root extract. Although ginseng has been used in traditional medicine for centuries, modern research is inconclusive about its biological effects. Preliminary clinical research indicates possible effects on memory, fatigue, menopause symptoms, and insulin response in people with mild diabetes. Out of 44 studies examined between 2005–2015, 29 showed positive, limited evidence, and 15 showed no effects. As of 2021, there is insufficient evidence to indicate that ginseng has any health effects. A 2021 review indicated that ginseng had “only trivial effects on erectile function or satisfaction with intercourse compared to placebo”. The constituents include steroid saponins known as ginsenosides, but the effects of these ginseng compounds have not been studied with high-quality clinical research as of 2021, and therefore remain unknown. As of 2019, the United States FDA and Federal Trade Commission have issued numerous warning letters to manufacturers of ginseng dietary supplements for making false claims of health or anti-disease benefits, stating that the “products are not generally recognized as safe and effective for the referenced uses” and are illegal as unauthorized “new drugs” under federal law. Concerns exist when ginseng is used chronically, potentially causing side effects such as headaches, insomnia, and digestive problems. Ginseng may have adverse effects when used with the blood thinner warfarin. Ginseng also has adverse drug reactions with phenelzine, and a potential interaction has been reported with imatinib, resulting in hepatotoxicity, and with lamotrigine. Other side effects may include anxiety, insomnia, fluctuations in blood pressure, breast pain, vaginal bleeding, nausea, or diarrhea.
- Zinc gluconate which has been used in lozenges for treating the common cold. However, controlled trials with lozenges which include zinc acetate have found it has the greatest effect on the duration of coldsInstances of anosmia (loss of smell) have been reported with intranasal use of some products containing zinc gluconate. In September 2003, Zicam faced lawsuits from users who claimed that the product, a nasal gel containing zinc gluconate and several inactive ingredients, negatively affected their sense of smell and sometimes taste. Some plaintiffs alleged experiencing a strong and very painful burning sensation when they used the product. Matrixx Initiatives, Inc., the maker of Zicam, responded that only a small number of people had experienced problems and that anosmia can be caused by the common cold itself. In January 2006, 340 lawsuits were settled for $12 million.
- Pyridoxine hydrochloride (vitamin B6) is usually well tolerated, though overdose toxicity is possible. Occasionally side effects include headache, numbness, and sleepiness. Pyridoxine overdose can cause a peripheral sensory neuropathy characterized by poor coordination, numbness, and decreased sensation to touch, temperature, and vibration.
‘Formula Fortuna’ allegedly is for lifting your mood. If I, however, tell you that you need to pay one Euro per day for the supplement, your mood might even change in the opposite direction.
What next?
I think I might design a dietary supplement against stupidity. It will not carry any of the risks of Hofer’s new invention but, I am afraid, it might be just as ineffective as Hofer’s ‘Formual Fortuna’.
Drip IV is “Australia’s first and leading mobile healthcare company specialising in assisting with nutritional deficiencies”. They claim to provide a mobile IV service that is prescribed and tailored individually to your nutritional needs. Treatment plans and customised infusions are determined by a medical team to suit individual requirements. They deliver vitamins, minerals and amino acids directly to the body via the bloodstream, a method they state allows for optimal bioavailability.
These claims are a little puzzling to me, not least because vitamins, minerals and amino acids tailored individually to the nutritional needs of the vast majority of people would mean administering nothing at all. But I guess that virtually every person who consults the service will get an infusion [and pay dearly for it].
The Australian Therapeutic Goods Administration (TGA) seems to have a similarly dim view on Drip IV. The TGA has just issued 20 infringement notices totalling $159,840 to the company and to one of its executive officers. The reason: unlawful advertising of intravenous infusion products to Australian consumers on a company website and social media. Ten notices totalling $133,200 were issued to the company and ten notices totalling $26,640 were issued to an executive officer. The TGA considers the intravenous infusion products to be therapeutic goods because of the claims made about them, and the advertising to be unlawful because the advertisements allegedly:
- contained prohibited representations, such as claims regarding cancer.
- contained restricted representations such as that the products would alleviate fatigue caused by COVID-19, assist in the treatment of Graves’ Disease and Alzheimer’s Disease, and support the treatment of autoimmune diseases such as Multiple Sclerosis. No TGA approval had been given to make such claims.
- referred to ingredients that are prescription only, such as glutathione. Prescription medicines cannot be advertised directly to the public in Australia.
- contained a statement or picture suggesting or implying the products were ‘TGA Approved’. Advertising of therapeutic goods cannot include a government endorsement.
- contained a statement or picture expressing that the goods were ‘miraculous’.
Vitamin infusions have become very popular around the globe. There are now thousands of clinics offering this service, and many of them advertise aggressively with claims that are questionable. Here is just one example from the UK:
Modern life is hectic. If you are looking to boost your wellbeing, increase your energy levels, lift your mood and hydrate your body, Vitamin IV Infusions are ideal. Favoured by celebrities such as Madonna, Simon Cowell and Rihanna, Vitamin IV Infusions are an easy, effective way of delivering vitamins, minerals and amino acids directly into your bloodstream via an IV (intravenous) drip. Vitamins are essential for normal growth and staying healthy – but our bodies can’t produce all of the nutrients we need to function and thrive. That’s why more than one in three people take daily vitamin supplements – often without realising that only 15% of the active nutrients consumed orally actually find their way into their bloodstream. With Vitamin IV Infusions, the nutrients enter your bloodstream directly and immediately, and are delivered straight to your cells. We offer four different Vitamin IV Infusions, so you can choose the best combination for your personal needs, while boosting your general health, energy and wellbeing.
My advice to consumers is a little different and considerably less costly:
- to ensure you get enough vitamins, minerals, and amino acids, eat a balanced diet;
- to boost your well-being, sit down and calculate the savings you made by NOT using such a service;
- to increase your energy levels, take a nap;
- to lift your mood, recount the money you saved and think of what nice things you might buy with it;
- to hydrate your body drink a glass of water.
Perhaps it is time the authorities in all countries had a look at what these clinics are offering and what health claims they are making. Perhaps it is time they act as the TGA just did.
The UK medical doctor, Sarah Myhill, has a website where she tells us:
Everyone should follow the general approach to maintaining and restoring good health, which involves eating a paleo ketogenic diet, taking a basic package of nutritional supplements, ensuring a good night’s sleep on a regular basis and getting the right balance between work, exercise and rest. Because we live in an increasingly polluted world, we should probably all be doing some sort of detox regime.
She also happens to sell dietary supplements of all kinds which must surely be handy for all who want to follow her advice. Dr. Myhill boosted her income even further by putting false claims about Covid-19 treatments online. And that got her banned from practicing for nine months after a medical tribunal.
She posted videos and articles advocating taking vitamins and other substances in high doses, without evidence they worked. The General Medical Council (GMC) found her recommendations “undermined public health” and found some of her recommendations had the potential to cause “serious harm” and “potentially fatal toxicity”. The tribunal was told she uploaded a series of videos and articles between March and May 2020, describing substances as “safe nutritional interventions” which she said meant vaccinations were “rendered irrelevant”. But the substances she promoted were not universally safe and have potentially serious health risks associated with them, the panel was told. The tribunal found Dr. Myhill “does not practice evidence-based medicine and may encourage false reassurance in her patients who may believe that they will not catch Covid-19 or other infections if they follow her advice”.
Dr. Myhill previously had a year-long ban lifted after a General Medical Council investigation into her claims of being a “pioneer” in the treatment of chronic fatigue syndrome. In fact, the hearing was told there had been 30 previous GMC investigations into Dr. Myhill, but none had resulted in findings of misconduct.
Dr. Myhill is also a vocal critic of the PACE trial and biopsychosocial model of ME/CFS. Dr. Myhill’s GMC complaint regarding a number of PACE trial authors was first rejected without investigation by the GMC, after Dr. Myhill appealed the GMC stated they would reconsider. Dr. Myhill’s action against the GMC for failing to provide reasoning for not investigating the PACE trial authors is still continuing and began a number of months before the most recent GMC instigation of her practice started.
The recent tribunal concluded: “Given the circumstances of this case, it is necessary to protect members of the public and in the public interest to make an order suspending Dr. Myhill’s registration with immediate effect, to uphold and maintain professional standards and maintain public confidence in the profession.”
The global interest in dieting has increased, and many people have become obsessed with certain fad diets, assuming they are magic bullets for their problems. A fad diet is a popular dietary pattern known to be a quick fix. This review article explores the current evidence related to the health impacts of (amongst others) detox diets (DDs). DDs are interventional diets specifically designed for toxins elimination, health promotion, and weight management. They involve multiple approaches, including total calorie restriction, dietary modification, or juice fasts, and often the use of additional minerals, vitamins, diuretics, laxatives, or ‘cleansing foods’. Some of the many DDs used today are listed below:
| Diet type | Duration | Foods allowed | Proposed claims |
| Liver cleansing diet | 8 weeks | Plant-based, dairy-free, low-fat, high-fiber, unprocessed foods are allowed. Epsom salt and liver tonics are also consumed. | Improved energy levels and liver function Toxins removal Improved immune response Efficient metabolism of fats and better weight control |
| Lemon detox diet/Master cleanser | 10 days | A liquid-only diet based on purified water, lemon juice, tree syrup, and cayenne pepper. A mild laxative herbal tea and sea salt water is also incorporated. | Toxins removal Shiny hair, glowing skin, and strong nails Weight loss |
| The clean cleanse | 21 days | Breakfast and dinner comprise probiotic capsules, cleanse supplements and cleanse shakes. A solid meal in lunch while avoiding gluten, dairy, corn, soy, pork, beef, refined sugars, some fruits, and vegetables. | Toxins removal Improved energy, digestion, sleep, and mental health Reduction in joint pains, headaches, constipation, and bloating |
| Martha’s vineyard detox diet | 21 days | Herbal teas, vegetable soups and juices, specially formulated tablets, powders and digestive enzymes are on the menu. | Weight loss Toxins removal Improved energy levels |
| Weekend wonder detox | 48 h | Protein-rich meals salads, detox-promoting superfoods, and beverages. Healthy lifestyle, spa treatments, and herbal remedies. | Toxins removal Improved organ function Strengthen body Enhance beauty |
| Fat flush | 2 weeks | Large meals are replaced with dilute cranberries, hot water with lemon, pre-prepared cocktails, supplements, and small meals | Toxins removal Reduced stress Weight loss Improved liver function |
| Blueprint cleanse | 3 days | Consumption of six pre-prepared vegetable and fruit juices is allowed per day. | Toxins removal |
| The Hubbard purification rundown | Several weeks | Niacin doses along with sustained consumption of vitamin-A, B, C, D, and E. Daily exercise with balanced meals. Restriction of alcohol and drugs. Sitting in a sauna for ≤ 5 h each day. | Toxins removal from fat stores Improved memory and intelligence quotient Better blood pressure and cholesterol levels |
Currently, there is no good clinical evidence for the effectiveness of DDs and some evidence to suggest they might do harm. Many of the DD are liquid-based, low-calorie, and nutrient-poor. For example, a part of BluePrint Cleanse, Excavation Cleanse, provides only 19 g protein and 860 kcal/day which is far below the actual requirement. Food and Agriculture Organization (FAO) recommends a minimum of 0.83 g/kg body weight of high-quality protein and 1,680 kcal/day for an adult. DDs may also induce stress, raise cortisol levels, and increase appetite, resulting in binge eating and weight gain.
As no convincing positive evidence exists for DDs and detox products, their use needs to be discouraged by health professionals. Moreover, regulatory review and adequate safety monitoring should be considered.
Dietary supplements are touted for cognitive protection, but supporting evidence is mixed. COSMOS-Mind tested whether daily administration of cocoa extract (containing 500 mg/day flavanols) versus placebo and a commercial multivitamin-mineral (MVM) versus placebo improved cognition in older women and men.
COSMOS-Mind, a large randomized two-by-two factorial 3-year trial, assessed cognition by telephone at baseline and annually. The primary outcome was a global cognition composite formed from mean standardized (z) scores (relative to baseline) from individual tests, including the Telephone Interview of Cognitive Status, Word List and Story Recall, Oral Trail-Making, Verbal Fluency, Number Span, and Digit Ordering. Using intention-to-treat, the primary endpoint was change in this composite with 3 years of cocoa extract use. The pre-specified secondary endpoint was change in the composite with 3 years of MVM supplementation. Treatment effects were also examined for executive function and memory composite scores, and in pre-specified subgroups at higher risk for cognitive decline.
A total of 2262 participants were enrolled (mean age = 73y; 60% women; 89% non-Hispanic White), and 92% completed the baseline and at least one annual assessment. Cocoa extract had no effect on global cognition (mean z-score = 0.03, 95% CI: -0.02 to 0.08; P = .28). Daily MVM supplementation, relative to placebo, resulted in a statistically significant benefit on global cognition (mean z = 0.07, 95% CI 0.02 to 0.12; P = .007), and this effect was most pronounced in participants with a history of cardiovascular disease (no history: 0.06, 95% CI 0.01 to 0.11; history: 0.14, 95% CI -0.02 to 0.31; interaction, nominal P = .01). Multivitamin-mineral benefits were also observed for memory and executive function. The cocoa extract by MVM group interaction was not significant for any of the cognitive composites.
The authors concluded that the Cocoa extract did not benefit cognition. However, COSMOS-Mind provides the first evidence from a large, long-term, pragmatic trial to support the potential efficacy of a MVM to improve cognition in older adults. Additional work is needed to confirm these findings in a more diverse cohort and to identify mechanisms to account for MVM effects.
This trial certainly has a few stunning features. For instance, its sample size was impressive and its follow-up period long. But it also has a few weak points. The study was conducted remotely via mail or telephone which means that compliance was impossible to control. Moreover, the outcome measures were subjective, and blinding was not checked. In addition, I fail to see a plausible mechanism of action. Most importantly, the generalizability of the results to the population at large seems questionable. It might make sense that older individuals many of whom might have low vitamin levels can profit from MVM. Whether this is also true for younger people who are well-nourished might be a different matter.
Many older adults commonly take multivitamin-multimineral (MVM) supplements to promote health. Yet, evidence on the use of daily MVMs on invasive cancer is limited.
The objective of this study was therefore to determine if a daily MVM decreases total invasive cancer among older adults. For this purpose, a team of researchers performed a randomized, double-blind, placebo-controlled, 2-by-2 factorial trial of a daily MVM and cocoa extract for prevention of cancer and cardiovascular disease (CVD) among 21,442 US adults (12,666 women aged ≥65 y and 8776 men aged ≥60 y) free of major CVD and recently diagnosed cancer. The intervention phase was from June 2015 through December 2020. This article reports on the MVM intervention.
Participants were randomly assigned to daily MVM or placebo. The primary outcome was total invasive cancer, excluding nonmelanoma skin cancer. Secondary outcomes included major site-specific cancers, total CVD, all-cause mortality, and total cancer risk among those with a baseline history of cancer.
During a median follow-up of 3.6 y, invasive cancer occurred in 518 participants in the MVM group and 535 participants in the placebo group (HR: 0.97; 95% CI: 0.86, 1.09; P = 0.57). No significant effect was observed of a daily MVM on breast cancer (HR: 1.06; 95% CI: 0.79, 1.42) or colorectal cancer (HR: 1.30; 95% CI: 0.80, 2.12). The researchers observed a protective effect of a daily MVM on lung cancer (HR: 0.62; 95% CI: 0.42, 0.92). The composite CVD outcome occurred in 429 participants in the MVM group and 437 participants in the placebo group (HR: 0.98; 95% CI: 0.86, 1.12). MVM use did not significantly affect all-cause mortality (HR: 0.93; 95% CI: 0.81, 1.08). There were no safety concerns.
The authors concluded that a daily MVM supplement, compared with placebo, did not significantly reduce the incidence of total cancer among older men and women. Future studies are needed to determine the effects of MVMs on other aging-related outcomes among older adults.
This is an excellent and important study with clear findings. Nevertheless, the authors insist that several limitations should be considered. First, the COSMOS intervention was relatively short to detect a potential small-to-moderate effect on cancer outcomes given the long duration of time typically required for nutritional interventions to potentially reduce cancer risk. Second, the secondary and exploratory analyses should be interpreted with caution, especially given an overall lack of effect of an MVM on the primary outcome of total invasive cancer. Third, the authors successfully leveraged existing cohorts with mass mailings to expedite recruitment and randomization of 21,442 participants into COSMOS. However, generalizability may be limited, with modest diversity of 10% non-Whites and 2.6% Hispanics plus healthy volunteer bias for participants willing and eligible to enroll in a mail-based clinical trial.
Traditional, complementary, and alternative medicine (TCAM) – as most of my readers know, I prefer the abbreviation SCAM for so-called alternative medicine – refers to a broad range of health practices and products typically not part of the ‘conventional medicine’ system. Its use is substantial among the general population. TCAM products and therapies may be used in addition to, or instead of, conventional medicine approaches, and some have been associated with adverse reactions or other harms.
The aims of this systematic review were to identify and examine recently published national studies globally on the prevalence of TCAM use in the general population, to review the research methods used in these studies, and to propose best practices for future studies exploring the prevalence of use of TCAM.
MEDLINE, Embase, CINAHL, PsycINFO, and AMED were searched to identify relevant studies published since 2010. Reports describing the prevalence of TCAM use in a national study among the general population were included. The quality of included studies was assessed using a risk of bias tool developed by Hoy et al. Relevant data were extracted and summarised.
Forty studies from 14 countries, comprising 21 national surveys and one cross-national survey, were included. Studies explored the use of TCAM products (e.g. herbal medicines), TCAM practitioners/therapies, or both. Included studies used different TCAM definitions, prevalence time frames and data collection tools, methods and analyses, thereby limiting comparability across studies. The reported prevalence of use of TCAM (products and/or practitioners/therapies) over the previous 12 months was 24–71.3%.
The authors concluded that the reported prevalence of use of TCAM (products and/or practitioners/therapies) is high, but may underestimate use. Published prevalence data varied considerably, at least in part because studies utilise different data collection tools, methods and operational definitions, limiting cross-study comparisons and study reproducibility. For best practice, comprehensive, detailed data on TCAM exposures are needed, and studies should report an operational definition (including the context of TCAM use, products/practices/therapies included and excluded), publish survey questions and describe the data-coding criteria and analysis approach used.
[Trends in prevalence of TCAM use by country for countries with at least two data collection waves from a nationally representative study. For data collected over several years (e.g. 2007–2009), the prevalence data are plotted at the end of the data collection period (e.g. 2009). Solid and perforated lines between consecutive points are for illustrative purposes only and are not intended to represent linearity. NHANES National Health and Nutrition Examination Survey, NHIS National Health and Interview Survey, SLAN Survey of Lifestyle, Attitudes and Nutrition.]
The review discloses that the prevalence reported across countries ranges from 24 to 71%. This huge variability is not very surprising; some of the many reasons for this phenomenon include:
- different TCAM definitions,
- different prevalence time frames,
- different data collection tools,
- different methods of analyzing the data.
Despite these problems, the information summarized in the review is fascinating in several respects. For me, the most interesting message here is this: the plethora of claims that SCAM use is increasing are not supported by sound evidence.
The US Food and Drug Administration created the Tainted Dietary Supplement Database in 2007 to identify dietary supplements adulterated with active pharmaceutical ingredients (APIs). This article compared API adulterations in dietary supplements from the 10-year time period of 2007 through 2016 to the most recent 5-year period of 2017 through 2021. Its findings are alarming:
- From 2007 through 2021, 1068 unique products were found to be adulterated with APIs.
- Sexual enhancement and weight-loss dietary supplements are the most common products adulterated with APIs.
- Phosphodiesterase-5 inhibitors are commonly included in sexual enhancement dietary supplements.
- A single product can include up to 5 APIs.
- Sibutramine, a drug removed from the market due to cardiovascular adverse events, is the most included adulterant API in weight loss products.
- Sibutramine analogues, phenolphthalein (which was removed from the US market because of cancer risk), and fluoxetine were also included.
- Muscle-building dietary supplements were commonly adulterated before 2016, but since 2017 no additional adulterated products have been identified.
The authors concluded that the lack of disclosure of APIs in dietary supplements, circumventing the normal procedure with clinician oversight of prescription drug use, and the use of APIs that are banned by the Food and Drug Administration or used in combinations that were never studied are important health risks for consumers.
The problem of adulterated supplements is by no means new. A similar review published 4 years ago already warned that “active pharmaceuticals continue to be identified in dietary supplements, especially those marketed for sexual enhancement or weight loss, even after FDA warnings. The drug ingredients in these dietary supplements have the potential to cause serious adverse health effects owing to accidental misuse, overuse, or interaction with other medications, underlying health conditions, or other pharmaceuticals within the supplement.”
These papers relate to the US where supplement use is highly prevalent. The harm done by adulterated products is thus huge. If we focus on Chinese or Ayurvedic supplements, the problem might even be more serious. In 2002, my own review concluded that adulteration of Chinese herbal medicines with synthetic drugs is a potentially serious problem which needs to be addressed by adequate regulatory measures. Twenty years later, we seem to be still waiting for effective regulations that protect the consumer.
Progress in medicine, they say, is made funeral by funeral!
Due to polypharmacy combined with the rising popularity of so-called alternative medicines (SCAM), oncology patients are at particular risk of drug-drug interactions (DDI) or herb-drug interactions (HDI). Caution is therefore indicated.
The aims of this study were to assess DDI and HDI in outpatients taking oral anticancer drugs.
All prescribed and non-prescribed medications, including SCAM, were prospectively collected by hospital pharmacists during a structured interview with the patient. DDI and HDI were analyzed using four interaction software programs: Thériaque®, Drugs.com®, Hédrine, and Memorial Sloan Kettering Cancer Center (MSKCC) database. All detected interactions were characterized by severity, risk, and action mechanism. The need for pharmaceutical intervention to modify drug use was determined on a case-by-case basis.
294 patients were included, with a mean age of 67 years. The median number of chronic drugs per patient was 8 [1-29] and 55% of patients used at least one SCAM. At least 0ne interaction was found for 267 patients (90.8%): 263 (89.4%) with DDI, 68 (23.1%) with HDI, and 64 (21.7%) with both DDI and HDI. Only 13% of the DDI were found in Thériaque® and Drugs.com® databases, and 125 (2.5%) were reported with a similar level of risk on both databases. 104 HDI were identified with only 9.5% of the interactions found in both databases. 103 pharmaceutical interventions were performed, involving 61 patients (20.7%).
The authors concluded that potentially clinically relevant drug interactions were frequently identified in this study, showing that several databases and structured screening are required to detect more interactions and optimize medication safety.
This figure of potential HDIs is high – much higher than in most previous studies. A possible explanation could be that the study was carried out in France where the use of herbal remedies is considerable. As some HDIs can cause serious problems for patients, my advice is to think twice about using herbal remedies while taking prescription drugs. I think this advice is sound regardless of whether someone is suffering from cancer or any other condition.
If you have been following my blog for a while, you probably know the answer to this question. A recent article published in JAMA re-emphasizes it in an exemplary fashion:
According to National Health and Nutrition Examination Survey data, 52% of surveyed US adults reported using at least 1 dietary supplement in the prior 30 days and 31% reported using a multivitamin-mineral supplement. The most commonly cited reason for using supplements is for overall health and wellness and to fill nutrient gaps in the diet. Cardiovascular disease and cancer are the 2 leading causes of death and combined account for approximately half of all deaths in the US annually. Inflammation and oxidative stress have been shown to have a role in both cardiovascular disease and cancer, and dietary supplements may have anti-inflammatory and antioxidative effects.
Objective To update its 2014 recommendation, the US Preventive Services Task Force (USPSTF) commissioned a review of the evidence on the efficacy of supplementation with single nutrients, functionally related nutrient pairs, or multivitamins for reducing the risk of cardiovascular disease, cancer, and mortality in the general adult population, as well as the harms of supplementation.
Population Community-dwelling, nonpregnant adults.
Evidence Assessment The USPSTF concludes with moderate certainty that the harms of beta carotene supplementation outweigh the benefits for the prevention of cardiovascular disease or cancer. The USPSTF also concludes with moderate certainty that there is no net benefit of supplementation with vitamin E for the prevention of cardiovascular disease or cancer. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with multivitamins for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with single or paired nutrients (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined.
Recommendation The USPSTF recommends against the use of beta carotene or vitamin E supplements for the prevention of cardiovascular disease or cancer. (D recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of multivitamin supplements for the prevention of cardiovascular disease or cancer. (I statement) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of single- or paired-nutrient supplements (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer. (I statement)
The report also elaborates on potential harms:
For many of the vitamins and nutrients reviewed, there was little evidence of serious harms. However, an important harm of increased lung cancer incidence was reported with the use of beta carotene by persons who smoke tobacco or have occupational exposure to asbestos.
Excessive doses of vitamin supplements can cause several known adverse effects; for example, moderate doses of vitamin A supplements may reduce bone mineral density, and high doses may be hepatotoxic or teratogenic. Vitamin D has potential harms, such as a risk of hypercalcemia and kidney stones, when given at high doses. The potential for harm from other supplements at high doses should be carefully considered.
There is nothing new here, of course. I (and others) have been trying to get these points across for many years. But it is nevertheless most gratifying to see the message repeated by a top journal such as JAMA. I hope JAMA is more successful than I was in changing the behavior of the often all too gullible public!
