When is it time to take them and what the science really says
Srinagar, Aug 16: Vitamin supplements can be a convenient way to fill nutritional gaps in our diets — but they’re far from a cure-all. The global market for vitamin and mineral supplements is booming, valued at around $32.7 billion (£24.2bn) according to a BBC report. In fact, more than 74% of Americans and about two-thirds of Britons report using them in hopes of improving their health.
Yet despite their popularity, supplements remain controversial. Some studies suggest they offer little to no health benefit, while others indicate potential risks. So what does the science actually say? Should everyone be taking vitamins — or only certain people? And do we really need them at all? As per experts
Why Do People Take Vitamins and Minerals?
Vitamins and minerals are essential nutrients our bodies can’t produce on their own. That means we must get them through our diet. For example: Vitamin A is crucial for vision and skin health.
Vitamin C supports the immune system.
Vitamin K helps with blood clotting.
Key minerals like calcium, magnesium, selenium, and potassium play a range of important roles, from bone strength to heart function. These nutrients are called micronutrients because we need them in small amounts — unlike macronutrients such as carbohydrates, proteins, and fats, which our bodies require in larger quantities. Ideally, we should be getting all these nutrients from a balanced diet rich in fruits, leafy greens, whole grains, nuts, dairy, and fish. But the reality is that many people fall short. The rise of fast food and ultra-processed meals means convenience often outweighs nutrition.
As one study put it, “The average individual is eating only half the recommended amount of fruits and vegetables,” highlighting a growing dietary gap that supplements aim to fill.
Bess Dawson-Hughes, a senior scientist at the US Department of Agriculture’s Human Nutrition Research Center on Aging, and professor of medicine at Tufts University. “So if you’re leaning in that direction, then you are probably missing out on some essential nutrients.”
Meanwhile, according to the National Institutes of Health (NIH) in the US, excess vitamin A can cause “severe headache, blurred vision, nausea, dizziness, muscle aches, and problems with coordination. In severe cases, getting too much preformed vitamin A can even lead to coma and death.”
The clinical trials that have been done on vitamins and minerals sometimes have contradictory results, and suggest that whether you will benefit from taking vitamin supplements depends on who you are, as well as the exact micronutrient the supplement contains.
Should You Be Taking Vitamin D Supplements?
While it’s generally unwise to exceed the recommended daily allowance for antioxidants, the picture is more nuanced when it comes to other nutrients — especially vitamin D.
Why Vitamin D Matters
Vitamin D is crucial for building and maintaining strong bones, yet many people don’t get enough of it. Technically, vitamin D isn’t a true vitamin, as our bodies can produce it naturally when our skin is exposed to sunlight. It’s also found in some foods, but dietary sources alone are often insufficient.
In regions with limited sunlight, especially during the winter, this becomes a problem. That’s why public health guidelines in the UK recommend that everyone take a vitamin D supplement between October and March. Similar advice applies to anyone living north of 37 degrees latitude (roughly the latitude of Santa Cruz, California) or south of 37 degrees latitude in the Southern Hemisphere.
What Does the Research Say?
One of the largest studies on vitamin D is the VITAL trial, led by Dr. JoAnn Manson and involving over 25,000 U.S. adults. The study investigated whether daily vitamin D or omega-3 supplements could reduce the risk of cancer, heart disease, or stroke in people with no prior history of these conditions.
The results were mixed:
No overall reduction in cardiovascular disease, stroke, or cancer rates.
But: A 17% reduction in cancer deaths among those taking vitamin D.
Among participants who took vitamin D for two years or more, there was a:
25% reduction in cancer mortality, and
17% reduction in advanced metastatic cancer.
“It may be that vitamin D affects the biology of tumor cells — making them less invasive and less likely to metastasize — but it doesn’t appear to prevent the initial development of cancer,” explains Dr. Manson.
Other Benefits and Limitations
The VITAL trial also found that vitamin D supplements significantly lowered the incidence of autoimmune diseases, such as rheumatoid arthritis and psoriasis.
However, when it comes to bone health — perhaps the most commonly cited reason for taking vitamin D — the findings are less conclusive. An early 2000s French study showed that older adults, particularly women in care homes, could benefit from supplementation. But more recent trials, including VITAL, ViDA, and D-Health, found no significant reduction in fractures or falls from taking vitamin D.
One possible explanation? Many trial participants may have already had adequate vitamin D levels, meaning extra supplementation had little effect. As Bess Dawson-Hughes puts it, “The average American eats only half the recommended amount of fruits and vegetables,” which can lead to broader nutrient gaps — but not necessarily vitamin D deficiency in all cases.
So when should you actually take Vitamin supplements?
According to experts intriguingly, evidence is starting to grow that popping a daily multivitamin could be beneficial for health, particularly for older adults.
Manson’s physician’s health study II, which began over 20 years ago, found that the risk of being diagnosed with cancer was 8% lower in people who took a daily multivitamin for 11 years. The greatest benefit was in older participants who were above the age of 70, who had an 18% reduction in cancer with the multivitamin assignment compared to the placebo group.
For most people, vitamin supplements aren’t necessary if you’re eating a healthy, balanced diet — whole foods provide not only better-absorbed nutrients but also additional health benefits like fibre. Both JoAnn Manson and Bess Dawson-Hughes agree: food should come first.
However, supplements can play a useful role in specific cases. Those who may benefit include:
Older adults (60+) for potential cancer and cognitive benefits
Pregnant women, who need folic acid to prevent birth defects
Vegetarians or those who eat little fish, who may lack omega-3s
People with absorption disorders or those on certain medications
Nursing home residents, who often need vitamin D and calcium
Ultimately, while supplements aren’t a magic fix, they can act as a nutritional safety net — particularly for those at risk of deficiencies. Just remember: more isn’t better, and exceeding recommended doses can do more harm than good.
