Basically, there was nothing, zero, nada, no evidence to strongly advocate the continued use of these vitamins and supplements if you’re trying to decrease your chances of having a heart attack, stroke or death.

Thirty billion dollars. That’s how much the US spends every year on vitamins and supplements. Even more astounding, the global vitamin, mineral and supplements market is expected to reach $186.95 billion by 2025, from $106.80 billion in 2017 growing at a rate of 7.3 percent during the forecast period of 2018 to 2025.

Unfortunately, a recent review providing the most comprehensive analysis of their effects concluded that most of that money is being wasted.

This “umbrella review” appeared in the Annals of Internal Medicine earlier this year and was a comprehensive report of randomized trials of vitamins and supplements that examined their effects on cardiovascular disease and overall mortality.

Including only randomized trials was a great choice. Observational studies of vitamin and supplement usage are plagued by what’s known as “healthy user bias” ─ individuals who choose to take vitamins often engage in other healthful behaviors. Time and again, vitamins that looked promising in observational studies failed in large randomized trials.

Now we have all of the best data surrounding vitamins and supplements in one place, which allows me to say the following: there is no high-quality evidence that any vitamin or supplement has a beneficial effect on overall mortality.

The analysis included studies of 24 different interventions, comprising of 277 randomized trials and nearly a million patients. And, basically, there was nothing,─zero, nada, no evidence to strongly advocate the continued use of these vitamins and supplements if you’re trying to decrease your chances of having a heart attack, stroke or death.

The only intervention that had even moderate-quality evidence for protection against all-cause mortality was reducing salt intake, which, frankly, doesn’t sound like a vitamin or supplement to me.

To give fair play to the other findings, there was low-quality evidence that omega-3 fatty acids might protect against heart attacks and heart disease and that folic acid might protect against stroke. There was, however, moderate-quality evidence that a combination of calcium and our old friend vitamin D increased the risk for stroke.

But all of these effects were pretty small.

Why? Well, let’s remember that vitamins were, by and large, identified via their deficiency syndromes. We know that vitamin C is vital for life because without it, people get scurvy. But there has never been much rationale as to why a super-intake of any of these chemicals would give super-benefits to health.

Of course, if you don’t eat a nutritious variety of foods, some supplements might help you get adequate amounts of essential nutrients. However, supplements can’t take the place of the variety of foods that are important to a healthy diet. Chances are, if you already eat and live healthy enough, you don’t need any supplementation at all.

However, some scientific evidence does show that some dietary supplements are beneficial for overall health and for managing certain health conditions. For example, in the right patient, calcium and vitamin D are important for keeping bones strong and reducing bone loss. Folic acid decreases the risk of certain birth defects.

Other supplements, however, truly need more study to determine their value. Remember that the US Food and Drug Administration and even our local FDA do not determine whether dietary supplements are effective before they are marketed.

Taking more than you need is always more expensive and can also raise your risk of experiencing side effects. For example, getting too much vitamin A can cause headaches and liver damage, reduce bone strength and cause birth defects. Excess iron causes nausea and vomiting and may damage the liver and other organs.

If you’re thinking of taking supplements, please don’t take them to treat a health condition that you’ve diagnosed yourself. It is always good to talk to your doctor about these things first. Don’t take supplements in place of, or in combination with, prescribed medications without your doctor’s approval.

Remember that the term “natural” doesn’t always mean safe. A supplement’s safety depends on many things, such as its chemical makeup, how it works in the body, how it is prepared, and the dose used.

Also, ask yourself these questions before taking any dietary supplement:

What are the potential benefits of this product for me?

Does this product have any safety risks?

How, when and for how long should I take it?

If you don’t know the answers to these questions, don’t ask your well-meaning neighbor for the answers and go talk to your doctor.

To be fair, the analysis I refer to only looked at mortality and cardiovascular outcomes. It remains possible that vitamins and supplements might improve subjective quality of life. But you know what else improves quality of life? Money. And based on this study, you might want to save yours when you’re walking down the vitamin aisle.