People often assume that vitamins and supplements can be taken in whichever quantities they want to take them because purchasing them doesn't require a prescription and they're "natural". But supplements and vitamins are more similar to other medications than you'd think and much like other meds, they are dose-dependent. This is why, when it comes to vitamins, more isn't necessarily better.
In the best scenario, doubling the dose of a vitamin or supplement will not be very useful, but if you do it frequently or with the wrong vitamin, it can even be dangerous. For example, excessive consumption of vitamin C "can interfere with the body’s ability to absorb copper, a metal that’s needed by the body. Too much phosphorous can inhibit the body’s absorption of calcium. The body cannot get rid of large doses of vitamins A, D, and K, and these can reach toxic levels when too much is taken,” according to the American Cancer Society.
Excessive intake of vitamins can lead to a condition called hypervitaminosis, which manifests itself through a variety of unpleasant symptoms and even organ damage depending on the specific vitamins that are overconsumed. Fat-soluble vitamins like vitamin D, E, A, and K are more likely to build up in the body than water-soluble ones, but even too much vitamin C, a water-soluble vitamin, can cause diarrhea and stomach pain when you take too much of it.
Therefore, it's best not to take vitamins unnecessarily. Also, if you do end up missing a day of the vitamin you're taking, just take the usual dosage, no need to double the dosage.
Vitamin D supplements are very popular, and they have been suggested to be effective at staving off many diseases, particularly cancer, and more recently Covid-19. This is because vitamin D deficiencies are among the most common deficiencies on the planet, which makes sense if think about it: since we get most of our vitamin D from the sun, and people who are frail are more likely to spend less time outside, which may result in a vitamin D deficiency.
This is why researchers say that we must be careful before we claim that any of these conditions are related to vitamin D deficiency. One particular example of a false causal relationship that has spurred a large number of studies is the link between low vitamin D and cancer. One of the largest studies investigating this correlation goes back to 2018. This randomized, placebo-controlled study involved 25,871 people and concluded the following, “Supplementation with vitamin D did not result in a lower incidence of invasive cancer or cardiovascular events than placebo.”
Therefore, it seems like low vitamin D levels are most likely not causing cancer, but it can manifest itself through other unpleasant symptoms, like the ones we've discussed in a previous article, so talk to your doctor if you need to take a vitamin D supplement if you're deficient in the vitamin.
While a good diet is always the primary source of vitamins and other beneficial nutrients, it doesn't mean that dietary supplements have no place in a person's life. As a matter of fact, in many cases, vitamins and supplements may actually be necessary and help people manage various conditions. For example, someone who is losing weight and is on a calorie-restricted diet can greatly benefit from a multivitamin supplement. Those who are lactose intolerant may benefit from calcium and vitamin D supplements, and vegans and vegetarians may require a B vitamin supplement.
Whether or not you need to take a supplement doesn't have to be diet-related either: for instance, those who don't get enough sun because they live in a cold climate may need to take a vitamin D supplement, women of childbearing age benefit from taking folic acid, and seniors may best off taking a Vitamin D, B Vitamins, and Calcium supplement because the production and retention of these vitamins decrease with age. Therefore, there is no need to shy away from supplements completely, especially if you need them to prevent or treat certain health conditions.
This flu season, you can save your money on all those fizzy vitamin C drinks and vitamin C supplements. This is because taking high doses of vitamin C to fend off a cold or make it pass faster was never a medical fact, but rather a misconstrued tip from a Nobel Prize-winning chemist that blew up in the media.
Several studies have proven these facts as well, most notably a 2013 Cochrane review article that involved over 11,000 participants and overtly concluded the following: "The failure of vitamin C supplementation to reduce the incidence of colds in the general population indicates that routine vitamin C supplementation is not justified". The same review also found mixed results in vitamin C's ability to reduce the severity and length of a cold.
Lastly, we'd like to point out to you that the market for dietary vitamins and supplement is, in fact, not as tightly regulated as you'd think, at least in many countries. In the United States, for example, "supplements do not need to be proven safe by the Food and Drug Administration," said Dena Champion, a registered dietitian at Ohio State University's Wexner Medical Center to US News.
Champion also pointed out that the FDA can only remove a supplement from the market after several reports of people having adverse reactions to the supplement have been submitted to them. One such example is the weight loss ingredient "ephedra", which took 16,000 cases of adverse health effects (including 155 deaths) to urge the FDA to ban ephedra in 2004.