Many people think that taking a daily cocktail of vitamins, minerals, antioxidants and other supplements is a prescription for a healthy diet. But it’s also likely that they don’t know whether the nutrients they’re taking are fat soluble, water soluble, or if they are getting more of some nutrients than they need.
Supplements, in general, are viewed as good for you, and people may think, “If one is good, then more is probably better.” But that’s not necessarily true.
Getting too many fat- or water-soluble nutrients, either from the food you eat or from supplements, can be dangerous. Vitamin and mineral supplements are serious business, and taking more than you need — unless you are under the care of your doctor — may be bad for your health.
Taking a vitamin or supplement as directed on the package label is considered to be safe, but not following directions can lead to problems.
“Excesses of all nutrients, from water, to iron, to water-soluble B vitamins, can potentially cause toxicities,” says Norman Hord, PhD, MPH, RD, associate professor in the department of Food Science and Human Nutrition at Michigan State University. People who take vitamins and minerals in amounts above the established upper limits of the Dietary Reference Intakes (DRIs) may harm tissues where the vitamin is stored in their body, Hord explains. That’s why you shouldn’t take more than the recommended amount.
Vitamins and other nutrients play essential roles in maintaining good health, but they need to be consumed in the proper amounts. Vitamins are classified into two types: water-soluble vitamins and fat-soluble vitamins. They are divided into these groups according to how they are dissolved and stored in your body. Fat-soluble vitamins reside in your body’s fatty tissue and liver and are used as needed by your body. By contrast, water-soluble vitamins dissolve in water and generally are not stored in your body.
Because water-soluble vitamins and nutrients dissolve in water, the continuous supply your body needs calls for a steady daily intake, from the foods you eat, from the supplements you take, or from a combination of foods and supplements. Vitamins C, B12, thiamin, niacin, riboflavin, tryptophan, pantothenic acid, biotin, and folic acid are all classified in the water-soluble category.
Water-soluble nutrients work best when you get them in the proper amounts. When you eat or take more than your body needs, the body adapts by absorbing just what it needs, and then it usually excretes the excess in your urine — but not always. A study in the August 2010 Journal of Nutrition Science and Vitaminology found that urinary excretion of certain vitamins and other nutrients was reduced when study participants fasted.
Vitamins A, D, E, and K are the fat-soluble vitamins. Unlike water-soluble vitamins, these vitamins dissolve in fat and are stored in body tissues. Because they are stored, over time they can accumulate to dangerous levels and can lead to a condition called hypervitaminosis, meaning excess amounts of a vitamin in the body, if more than the recommended amount is taken.
Exceeding the government set tolerable upper limits can be a problem. “There is a reason for the tolerable upper limits that needs to be respected. Research has shown at which levels nutrients can cause potential problems, and these numbers take into account all sources of vitamins and minerals from food, fortified food and supplements,” says Frechman.
When the level goes beyond the safe upper limits, vitamins can act like drugs, says Roberta Anding, MS, RD, spokesperson for the American Dietetic Association, director of sports nutrition at Texas Children’s Hospital, and dietitian for the Houston Texans pro football team. Excessive calcium intake, more than 2,500 mg a day, can interfere with kidney function, cause kidney stones and constipation, and interfere with the absorption of iron and zinc. One 2,500 mg calcium supplement is like drinking eight glasses of milk, which goes beyond the reasonable food level, explains Anding.
Fortified foods are another way people get additional nutrients. Historically, fortified foods were the way Americans filled some nutrient voids. Public health concerns over nutrient deficiencies led to production practices like adding iodine to salt, grains enriched with B vitamins and iron, and milk fortified with vitamins A and D.
But the combination of whole foods, supplements, and fortified foods raises safety concerns with experts. Eating fortified foods while also taking supplements can cause a person’s diet to exceed safe upper levels and potentially lead to a toxic buildup.
Six Brazil nuts, which weigh about 1 ounce, contain 544 micrograms of selenium, says Frechman. That’s a whopping 780% of the Daily Value of this trace mineral, which is only needed in small amounts.
The bottom line to remember is to consult a doctor or dietitian before you begin taking any supplement. A person trained to know the proper levels of every vitamin and mineral can recommend supplements that are safe for your body, according to your medical history, blood work and diet.
Are you currently taking supplements without physician supervision? Are you unsure of what you re taking and if it is too much? To learn more about our functional medicine program or to schedule an appointment, please call (304) 263-4927 today. Dr. Terry Chambers is a Board certified chiropractor and acupuncturist, licensed in WV, and trained to perform functional medicine.