In a previous column, I discussed the limited efficacy of the $14 billion Americans spend annually on cold and flu supplements. The bottom line was that we can get the vast majority of our immune-boosting vitamins from a diverse healthy diet, good sleep hygiene, stress control and early morning sunlight.
Now comes a massive meta-analysis from JAMA of 84 studies on vitamins and supplements. The aim of this review was to assess the benefits (or harms) of vitamins and minerals in healthy, non-pregnant adults in preventing cardiovascular disease and cancer. This review looked at beta-carotene (precursor to vitamin A), vitamin D and vitamin E. Here’s what the researchers found:
- Beta-carotene: supplementation associated with increased risk of lung cancer and cardiovascular mortality.
- Vitamins D and E: not associated with increased or decreased risk of all-cause mortality, cardiovascular disease or cancer. In summary, no benefit.
Based on these findings, the United States Preventive Services Taskforce 1) recommends against the use of beta-carotene or vitamin E supplements for the prevention of cardiovascular disease or cancer and 2) states that there’s insufficient evidence to assess the benefits or harms of multivitamins or other single or paired nutrient supplements for the prevention of cardiovascular disease or cancer.
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This is quite a definitive statement given that Americans spent $50 billion on multivitamins and supplements in 2021.
Conventional wisdom in medicine argues that multivitamins or nutrient supplements still have a role in certain populations like older adults, pregnant people or special dieters. But there is a lack of definitive consistent evidence for proven benefit of multivitamins in any of these populations. On an individual level, a better approach remains to identify the specific nutrient deficiency and address it with specific fortified foods or diet.
For example, we continue to recommend pregnant people take a prenatal vitamin, but the quality of evidence isn’t very high that this supplementation reduces the risk of a fetus being small for gestational age or developing neural tube deficits. It’s more likely that the folic acid present in the prenatal vitamin is the primary actor in healthy fetal development. So, it may make more sense for pregnant people to take folic acid only, or eat more folic acid-fortified cereal-grain products.
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Along those lines, I think this study presents a good opportunity to review how a wide-ranging healthy diet can provide some of the most important vitamins and minerals. Here are a few of my favorites:
Vitamin D is key not only for bone health and immunity, but for mood and a healthy circadian rhythm. The best natural source of natural vitamin D is sunlight, which converts precursor molecules in our skin to the active form of vitamin D from which we derive benefit. The best time of day to get vitamin D is early morning sun. Doing that right after awakening sets a healthy circadian rhythm for the day and also helps you avoid more harmful UVA and UVB rays that are present starting in the early afternoon.
Fatty fish like tuna and salmon are high in vitamin D. Eggs yolks and mushrooms also contain solid amounts of vitamin D. Note that the recommended daily allowance of vitamin D is 400-800 IU/day – most adults however need about 1,000-2,000 IU of vitamin D3 a day depending on how much sun they get and where they live. I get adequate amount of sun and take 2,000 IU a couple times a week.
Magnesium is important for blood pressure control and blood glucose control. It’s a key cofactor for over 300 enzymes that regulate protein synthesis and nerve function. Magnesium is required for the synthesis and activation of vitamin D, such that if you’re low in dietary magnesium, it doesn’t matter how much vitamin D you supplement with.
Unfortunately, our Western diet of refined grains and processed foods are poor sources of magnesium. An adequate amount of magnesium can be obtained from dark-green leafy vegetables, almonds, legumes like black beans and whole grains.
Omega-3 fatty acids form a key part of the structure of every cell we have. They are an “essential” fat – meaning the body cannot generate its own and we must obtain it from diet. These essential fatty acids are a major component of our brain, eye retina, skin and nails. They are involved in conducting signals between cells and are a source of energy. While a 2012 meta-analysis found that the heart-protective effects of fish oil were not as strong as we once thought, there is likely a benefit in those high risk for cardiovascular disease.
Mackerel, salmon and cod liver oil boast some of the highest levels of omega-3.
There are a total of eight essential B vitamins. Primarily, they function in converting sources of energy from carbohydrates, fats and proteins into energy. Fifteen percent of the population are deficient in vitamin B12, for example, particularly those who practice a vegan or vegetarian diet. Those who suffer from digestive disorders or who had gastrointestinal surgery might also be high-risk for vitamin B deficiency.
The main sources for vitamin B complex includes chicken, organ meats, eggs, seeds, nuts and fortified cereals and grains.
In most healthy adults, key vitamins and minerals can be obtained from a well-balanced diet and daily early morning sunlight. Supplementation might only be necessary in those who cannot get enough sunlight or who are elderly or suffer from high-risk conditions that make it difficult to consume vitamins from diet alone.
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Michael Daignault, MD, is a board-certified ER doctor in Los Angeles. He studied Global Health at Georgetown University and has a Medical Degree from Ben-Gurion University. He completed his residency training in emergency medicine at Lincoln Medical Center in the South Bronx. He is also a former United States Peace Corps Volunteer. Find him on Instagram @dr.daignault
