ADVERTISEMENTS OF dietary supplements span four pages in a Korean inflight magazine. “All in one capsule,” reads the description of one of the expensive products marketed to lure in the especially health-conscious consumers. Claiming to contain no less than five properties, those pills seem like a cure-all: heart strengthening, prevention of liver disease, anti-aging, stress reduction, and even sexual enhancement. Chances are you do not need to take them at all, and you may not experience any positive effect on your health in case you do. To make things worse, redundant vitamin intake could eventually cause harmful effects if the nutritional level reaches past the recommended value.
Vitamin supplements: what are we talking about?
Asked about vitamin supplements, many people admit taking them in order to fulfill their nutritional requirements and “feel” healthier*. Although users tend to know that vitamin supplements are not to be substitutes for a balanced diet, they also regard them as part of “a welfare plan,” according to Nutrition Journal. That is why some take them above the recommended amount to compensate for their less-than-healthy lifestyle**.
Vitamins are a category of micronutrients regarded as essential for their role in boosting metabolic processes and protecting us against disease. They can be broken down into 13 vitamin groups, where each one performs a different function and is acquired from different sources—mainly foods, but also intestinal bacteria for biotin and vitamin K, and sunlight for vitamin D***. Normally, a healthy diet and lifestyle will assure necessary levels of vitamin intake in our body. However, supplementation can be a remedy for certain people with a vitamin deficiency when they cannot get the amounts they need from their diet or when they suffer from a disease****.
Vitamin supplements come as both single and multivitamins. Multivitamins with minerals are the most popular, being “a combination of vitamins and minerals, and sometimes other ingredients as well,” according to the U.S. National Institutes of Health. Some labels state to contain three kinds of vitamins and at least one mineral*****, yet there is no standard and, depending on the brand, their composition can vary by the addition of minerals, herbs, and amino acids.
Despite the helpful additives, supplements do not act the same way or have the same positive effects as natural vitamins. Nutrients are better absorbed from food than from supplements, according to JAMA Internal Medicine. Higher effectiveness of food sources may come from how the vitamins interact with a wide array of other nutrients, a process supplements by themselves cannot replicate******. Hence, not only are the positive effects of vitamin supplementation not as high as we think, but also excessive intakes can turn out to be dangerous.
Not so innocuous: vitamins also have a limit
For the consumption of nutrients, daily recommendations set an upper limit, and vitamins are no exception. Appropriate intake levels may change depending on age, sex, and ultimately on each person—for which medical advice is strongly recommended.
Unfortunately, people tend to ignore the labels and take mega-doses in hopes of receiving higher benefits. While absorbing vitamins from food alone pose almost no risk of overdose, by the end of the day we may go way past the recommended values if our diet also includes fortified foods—food artificially enriched with vitamins—along with the vitamin pills*******.
Overdoing vitamins can be harmful both in the short and long-term. As noted in Healthline, vitamin toxicities, or hypervitaminosis, are most likely to occur with fat-soluble vitamins, such as A, D, E and K, since they cannot be excreted through urine and, therefore, stay longer in our body.
For instance, beta-carotene—an antioxidant that converts to vitamin A—has been related to lung cancer in smokers, and vitamin E with heart disease, while vitamin A with toxicity that can worsen rather than cure cancer, according to Better Health Channel. Vitamin D is “the most likely of all vitamins to cause overt toxicity”, according to the UK National Health Service, though this is a rare situation.
This does not mean consumption of water-soluble vitamins can be uncapped: research shows some connection between high dose of vitamin B6 and nerve damage, and vitamin C and nausea, fatigue, headaches, diarrhea, and kidney stones********.
Besides the potential harm of excessive vitamin supplements, there is the issue of the unfounded benefits attributed to the use of supplementation when there is no evidence.
Wonder pills: what supplements can and cannot do
Whether supplements may or may not have health benefits, they are not medicine. As reported in The Atlantic, dietary supplements are still being widely taken for the same purposes of treating or preventing ailments. Science has found a neutral or even negative effect of extra vitamin intake on the premise of preventing chronic conditions, like cardiovascular disease or cancer*********. Also, for mental health, B-vitamins supplements—except for vitamin B12—were proven to have no connection to improving anxiety**********.
Lee Duk-chul, MD and Family Medicine specialist at Severance Hospital, evaluated the hype about antioxidant vitamins—vitamins beta-carotene, C and E—in an interview with The Yonsei Annals. These vitamins were long argued to prevent chronic disease by inhibiting chemical imbalances in the body caused by a process called oxidation. Oxygen, although vital for life, can be destructive to cells, so it was thought that higher doses of antioxidants would significantly decrease the level of oxidation. “It is true, [those] vitamins are strong antioxidant[s]. But clinical trials [of supplements] give us another story,” Lee said. Our body still needs some oxidation for proper functioning, so a high dose of antioxidants could potentially be harmful and increase the risk of chronic disease.
This is not exclusive to those antioxidants. Current research tells us supplementation generally does not reduce death risks whatsoever***********. However, this does not mean taking supplementation is completely useless—it simply indicates no benefit for improving the average healthy person’s life. Supplements are still accepted as an effective means to ensure minimum nutrient intake when there is a nutrient deficiency. For such cases, “multivitamins are mostly useful to meet the daily requirement of vitamins. One capsule of multivitamins contains low levels of many vitamins and prevents vitamin deficiency,” as stated by Lee.
The American Academy of Family Physicians (AAFP) suggests supplements work for people with vitamin deficiencies due to health problems, a restricted diet, or a life phase. Some medical conditions require supplementation, according to Harvard Health Blog. Same goes for pregnant and lactating women, who are recommended to take vitamin D supplements and folic acid during pregnancy, elderly people who need vitamin D and vitamins otherwise difficult to absorb from food, and children between 6 months and 5 years, who should take vitamins A, C and D. Vegans may not need supplements to compensate for a B12 deficiency if they can have fortified almond milk instead************.
Besides that, vitamin D is a special case. Easily acquired through exposure to sunlight, our lifestyle could impede a natural intake of this essential vitamin. “Nowadays we have sunscreen for protection from UV light and modern people do not have enough time to exercise and do activities outdoors, so everybody needs some kind of vitamin D fortified food or supplementation,” Lee said. This is the only vitamin he recommends testing and supplementing if levels are below standards, while recommending fulfilling the rest of nutritional requirements through foods.
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Originally created to combat nutrient deficiency, vitamin supplements still remain popular even with our improved diets and living conditions. The bottles of vitamins on your shelf may be doing you more harm than good if you are already getting the intake you need from a balanced diet. Certainly, part of maintaining good health is doing the research before blindly following health trends.
* Harvard Men’s Health Watch
**** Intermountain Healthcare
***** U.S. National Health and Nutrition Examination Survey (NHANES)
****** Harvard Health
******* Mental Floss
******** Better Health Channel
********* The New York Times
*********** NBC News