I am frequently asked about which vitamin and mineral supplements (if any), my patients should take. Some people see supplements as an unnecessary waste of money, while others see them as a vital part of good nutrition. Most people view vitamin supplements as safe and harmless. Few people realize that taking over-the-counter vitamin supplements can be harmful even if taken as directed on the label. If you’re confused, you’re not alone. It’s complicated!
Here is what you need to know about taking vitamins:
Vitamins are vital nutrients that we need to eat in small quantities to maintain health. While a plant-based diet with small amounts of animal products can provide all the essential nutrients we need, most Americans eat fewer plants and more calorie-dense processed foods than are healthy.
Vitamin deficiencies in the US are common in spite of our plentiful food supply. The majority of Americans eat inadequate amounts of Vitamins D, E, K, and choline (a B-vitamin-like compound), and over a third of Americans don’t get enough vitamins C and A. We also don’t get enough potassium or minerals like Calcium and Magnesium which I’ll discuss in a separate article.
Do you get enough vitamins from your diet?
If you eat 2 to 3 cups of green leafy vegetables, 2-3 additional servings of fruit and vegetables, 3 servings of whole grains, a serving or two of nuts or seeds daily and eat seafood, chicken, or other meat several times a week and either get 2 servings of fortified dairy foods or fortified plant milk daily, then stop reading right here–You don’t need a vitamin supplement unless you have a health condition that increases your vitamin needs.
Most of us do not eat that well all the time.
On the days you do eat well, you don’t need any supplements. If you don’t eat 5 servings of fruit and vegetables daily, try to eat more. Taking a vitamin is a poor substitute for actual food and carries risks that are not present in real food.
Our nutrient needs are a delicate balance: Too little of a nutrient is harmful, but getting too much of it can be harmful too. More isn’t always better. Plant foods have many compounds that work together as built-in safeguards that prevent us from getting too much of a nutrient from our food, however, there are dangers in taking isolated nutrients in supplement form. Some vitamins like vitamin C are fairly safe even if you were to get up to 20 times the recommended intake (you might just get stomach issues and headache), while other vitamins like vitamin B3 (Niacin) can be harmful when just double the recommended intake is taken in supplement form (flushing, dizziness, nausea and vomiting, etc.) Taking too many B vitamins over time can promote cancer. Taking an excess of vitamin A is actually toxic and can cause gastrointestinal symptoms, rashes, hair loss, and even neurologic symptoms. All vitamins when taken in excess can have toxic effects. Serious side effects are most common when large doses of vitamins (more than the RDI–recommended daily intake) are taken over a long period of time. The %daily value (%DV) listed on the supplement’s label is an approximation of the RDI and can be used to determine if your supplement contains too much. Unless instructed by your doctor, avoid getting more than 100% of the DV daily from supplements.
The take-home message is that taking vitamin supplements to treat or prevent deficiency is safe and beneficial as long as you don’t take more than the RDI (100%DV).
Unfortunately, vitamin supplements marketed as daily multivitamins often contain unsafe amounts of some vitamins (more than the RDI) and too little of others, and no two brands of supplements contain the exact same ingredients. Supplements marketed for “healthy skin and hair,” “stress,” “energy” or other purposes often contain huge doses of vitamins. You need to make sure that you aren’t doubling up on any nutrients if you take more than one pill. You also want to make sure that you’re not getting large doses of vitamins in fortified processed foods like energy drinks and “nutrition” bars and shakes. Read the labels!
It’s important to realize that while vitamin supplements are potent medications, they are not regulated by the FDA. They often don’t contain what they say they do (more or less of an ingredient), or are contaminated with toxins like lead, or potential allergens like wheat, soy, or dairy. If you take vitamins on a regular basis, it is worthwhile to subscribe to consumerlab.com, an independent watchdog organization that tests supplements for contamination and accuracy of ingredients as well as price.
If you have gotten vague advice on supplements from your doctor in the past, there’s a good reason. Doctors are trained to recognize nutrient deficiencies and medical conditions but do not get training in nutrition unless they seek additional education after finishing medical school. If you have special nutritional needs, you will likely need to work with a doctor and a registered dietician.
There are groups of people who cannot get all their vitamins from their diet and need supplements:
- All vegans need to supplement vitamins B12 and K2, as well as zinc, calcium, and sometimes iron. Many strict vegetarians need these supplements too.
- Very picky eaters rarely get optimal amounts of vitamins D, E, K, or elements like magnesium, potassium, and zinc. However, some picky eaters get too much of some nutrients because they eat a limited diet. For example, picky eaters who drink large volumes of milk sometimes get copious amounts of vitamin D and calcium.
- People with food allergies may face challenges getting several nutrients.
- People who have frequent diarrhea can be depleted in Vitamin D, B vitamins as well as protein, iron, calcium, magnesium, and zinc.
- People with an elevated BMI (body mass index) are often deficient in vitamin D and may require a supplement of up to 2000IU daily.
- If you are actively dieting to lose weight, taking a multivitamin with the RDI of vitamins is a good idea.
- People with recent severe illness or chronic disease may need supplements depending on their illness and should consult a registered dietician.
I do NOT recommend daily long-term vitamin supplementation unless you have a medical condition that prevents nutrient absorption or one of the above conditions.
People being treated for cancer should not take vitamins unless instructed to by their oncologist since large doses of vitamins can promote cancer.
There is no evidence that athletes participating in intense training need more than the RDI (100% DV) of vitamins, even though they do need more calories, protein, potassium, and magnesium. The extra calories athletes need should supply the needed vitamins as long as they have a good diet. Athletes who are picky eaters may need a daily multivitamin.
Extra vitamin C helps athletes adapt to heat stress, (If you’re working out in extremely hot weather) but it’s better to get it from foods like fruit and vegetables throughout the day.
Which supplement should I take?
It’s virtually impossible to find a quality supplement without too much of at least one ingredient, but, if you and your doctor or dietician have determined that you need a multivitamin, the following vitamins are my top picks:
If you’re taking a vitamin just in case you don’t get enough vitamins in your diet: Flintstones Plus Immunity Support: 1 gummy daily. Yes, the dose on the bottle is 2 daily for ages 4 and up, but unless you’re treating a deficiency, one vitamin contains enough. If you’re dieting or have a known deficiency, take 2 daily.
A word about gummies: If you choose to take a gummy vitamin, always take it with a meal and brush your teeth well afterward to prevent tooth decay.
If you need a vitamin AND have been told by a physician to take iron: Kirkland Signature Daily Multivitamin once daily is for you.
These vitamins are not good sources of magnesium, an essential mineral that is deficient in most Americans’ diets. Magnesium is best taken at a different time of day from other minerals like zinc and iron. I will discuss this in detail in another article.
click here to find out about a smoothie that has all the fruit and vegetables you need–if you can drink it! (you still need to eat some nuts or seeds and another serving of Vitamin D daily in addition to seafood or meat twice a week.) I prefer to eat my vitamins in tasty foods throughout the day.
See my meal plan and recipes to get all your vitamins from food!
This general advice is intended for healthy people 13 years old and older and is not a substitute for the advice of your doctor.