Can You Take Too Many Vitamins or Supplements? - Ask a Nutritionist

Transcript:

Alyssa: Hi everyone. Welcome back to “Ask a Nutritionist” our weekly mini episode of Dishing Up Nutrition, where we answer questions from you, the listeners. I'm Alyssa, Registered Dietitian with Nutritional Weight & Wellness. Today's listener asked, can you take too many vitamins or supplements? As a dietitian, I frequently get asked about supplements.

Supplements can fill in nutritional gaps

Supplements can be beneficial to help correct nutrient deficiencies. First and foremost, I promote getting nutrients from real food. Supplements can serve as a tool helping to improve a person's nutritional status when their diet may be low in some areas, or they may be on a medication that depletes certain nutrients.

For instance, according to the FDA proton pump inhibitors, such as omeprazole used to treat reflux , can deplete magnesium from the body, causing magnesium in supplement form to possibly be a benefit. Some other nutrients people frequently benefit from supplementing include calcium, vitamin D and omega-3 fats.

Can you take too many vitamins or supplements?

The short answer to today's question, can you take too many vitamins or supplements, is yes. Dose matters. Taking more of something is not always better. Also, as a side note, before starting any supplement or considering starting multiple supplements, please consult with a qualified healthcare provider who is part of your team, who knows your health history, concerns, and current medications.

Keep a list of all your supplements and doses with you to share with your healthcare providers. Supplements may have negative interactions with certain medications or health conditions. Individual needs and responses to supplements vary. What is safe and effective for one person might not be right for another.

Start with consuming a well rounded, balanced diet

The ideal way to get all of our nutrients that you need is by consuming a well-rounded balanced diet. A person's age, genetics, medical conditions, medications and diet are all factors we consider when determining if a supplement is beneficial. Typically, vitamin supplements are safe to take when used responsibly. Today's talk is not meant to scare you. Most people do not develop toxicity. It is, however, intended to help you supplement more intentionally and safely. So let's get into it and dive a little deeper.

How common is it to experience vitamin toxicity?

First, let's discuss how common it is to experience vitamin toxicity. Then, which symptoms do we look out for, and which vitamins or minerals deserve a little bit more of our attention? When you get vitamins and minerals naturally from eating food, you are unlikely to have any cause of harm, even when nutrients are consumed in large amounts.

When supplements are taken at recommended doses, it is also uncommon to have vitamin toxicity Problems more often arise after the use of mega doses, or when taking multiple supplements that all contain some of the same nutrients resulting in excess amounts of one or more individual nutrients without you necessarily even realizing that you're getting that much.

Vitamin toxicity occurs when vitamins build up in the body to levels that cause harm. Symptoms vary widely depending on the vitamin involved. Common signs can include nausea or vomiting, diarrhea or constipation, fatigue, weakness, headaches, dizziness, nerve issues like tingling or numbness, joint or bone pain, and in severe cases, liver damage.

Overviewing water soluble & fat soluble vitamins

The 13 known essential vitamins can be separated into two groups. They're water soluble and fat soluble vitamins. Water soluble vitamins are readily excreted from the body. They're not easily stored in tissues. The water soluble vitamins include vitamin C and eight B vitamins. Since these vitamins are excreted through urine, they're less likely to cause issues when taken at high doses. Taking mega doses of some water soluble vitamins can still have potential negative side effects.

Vitamin C

For example, vitamin C or ascorbic acid has relatively low toxicity. In the body, it is used as an antioxidant to prevent damage to cells and for growth and repair of tissues in the body. Vitamin C is naturally found in foods like potatoes, citrus fruits, bell peppers, and strawberries.

Taking high doses of vitamin C, such as a thousand milligrams of vitamin C or more, more than once per day, can result in gastrointestinal disturbances, including diarrhea and cramping. Sometimes people take high amounts of vitamin C on purpose to help them relieve constipation.

It's important to note that in some people high dose vitamin C supplementation can also increase risk of kidney stones. No one wants that pain. For adults, it's generally recommended to not take more than 2000 milligrams of vitamin C daily from supplements.

Vitamin B3 

B vitamins are important to support metabolism. Vitamin B3 is also known as niacin and is naturally found in fish, meat, leafy greens, and whole grains. Therapeutically, niacin has been used to help manage cholesterol levels. People taking high doses of niacin can be at risk of experiencing what is known as the niacin flush. While generally harmless, niacin flush can be an early indicator of vitamin B3 toxicity.

With niacin flush, the high dose niacin results in blood vessels dilating. This is known as vasodilation. It leads to the skin reddening, along with feelings of itchiness, warmth and tingling in the skin. High-dose niacin should be avoided for those with gout as it can increase uric acid levels. Good news is most multivitamins and B complexes use a form of vitamin B3 niacin called niacinamide, which does not cause this flushing reaction.

B vitamins

Another concern with B vitamins and multivitamins that frequently get brought to our attention is urine turning to a neon yellow color. It looks alarming. It's a reaction from riboflavin, also known as vitamin B2. Riboflavin is yellow and naturally fluorescent when exposed to ultraviolet light. Bright colored urine due to the riboflavin reaction is not a sign of toxicity or malabsorption.

Riboflavin is naturally found in eggs, dairy, meat, salmon, leafy greens, and whole grains. In high doses, it has not been shown to be toxic. It quickly leaves the body when you urinate. No known upper tolerable intake for riboflavin supplementation has been set.

Fat soluble vitamins

The biggest vitamins to look out for are fat soluble vitamins. Fat soluble vitamins include vitamin A, D, E, and K. Unlike water soluble vitamins, fat soluble vitamins do not dissolve in water. They're easily stored in the tissues of the body. These vitamins are absorbed with dietary fat and stored in the liver and fatty tissues. They accumulate over time and excess amounts are not easily excreted.

Vitamin A

Let's walk through a few examples, including what toxicity can look like. Vitamin A is essential for your vision, immune function, and skin health. There are two sources of Vitamin A. Preformed vitamin A is found in organ meats like liver, fish, dairy products, and eggs.

And provitamin A carcinoids are ones that are turned into vitamin A by your body. Carcinoids are pigments that give red, yellow, and orange fruits and vegetables color. The most common provitamin carcinoid in foods and dietary supplements is beta carotene. Vitamin A from plant sources like beta carotene found in orange foods such as carrots and in supplements with beta carotene does not cause the same toxicity risk compared to getting too much preformed vitamin A from supplements.

Getting too much preformed vitamin A in supplements or certain medications can lead to acute vitamin A toxicity. People can experience several symptoms such as severe headache, blurred vision, nausea, and dizziness.

Vitamin D

Vitamin D is a fat soluble vitamin. We frequently discuss adequate Vitamin D is top priority because it's so important for overall health, but it is common to get met with some concern about taking too much since it's a fat soluble vitamin. Typically, I recommend taking somewhere between a thousand to 4,000 international units per day for adults.

Some even benefit from taking 5,000 international units daily. Some of my clients take 5,000 international units, vitamin D, two to three times per week. So they're getting the equivalent of about 1,400 to 2100 international units of vitamin D daily.

Monitoring your vitamin D levels can help in determining the right dosage to meet your needs and prevent toxicity. When a person is vitamin D deficient, we'll often supplement with a higher dose for a period of time to replete their vitamin D levels, maybe for three months, and then recheck levels and adjust supplements as needed.

Vitamin D toxicity generally requires high dose supplementation, often at least 10,000 international units per day or more long term for levels to really build up and get to an area of concern. The main concern with vitamin D toxicity is the buildup of calcium in the blood. This is known as hypercalcemia and can cause stomach upset, vomiting, frequent urination, weakness, bone pain, and even kidney issues such as kidney stones.

With vitamin D supplements, add up your vitamin D from all supplements, multivitamin, calcium, omega-3 supplements may all contain vitamin D. You may not need much additional vitamin D if you're already getting some in a multivitamin and/or calcium supplement. In general, it can be beneficial for your health to have your vitamin D levels checked and monitored.

You might be surprised that your levels are lower than you think, even while supplementing. Blood work is simple and a way to get reassurance that you're in a healthy vitamin D range.

Vitamin K

Vitamin K is an essential vitamin that plays a key role in blood clotting, wound healing and bone health. People with inadequate amounts of vitamin K in their system have a greater risk of bone fractures and bleeding. There are two different forms of vitamin K in the human body. Vitamin K1 is the main dietary form and is found in plant foods like leafy greens. Vitamin K2 is found in some animal products and fermented foods.

Bacteria living in your gut also produce vitamin K2. Vitamin K toxicity is rare. Vitamin K can interfere with blood thinning medications like Warfarin. People on this medication are advised to keep their vitamin K intake consistent, as large swings in intake could increase or decrease the anticoagulant effect of the Warfarin medication.

Consistent intake from day to day is key. Discuss your sources of vitamin K from foods and/or supplements with your doctor who may then adjust the dose of your medication to meet your preferences for foods and supplements.

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Iron

Iron is an essential mineral that is a vital part of hemoglobin found in red blood cells. It's not a vitamin, it's a mineral. Hemoglobin carries oxygen from the lungs to all cells in the body. You can get the recommended amounts of iron by eating a variety of foods like lean beef, chicken thighs, white beans, lentils, nuts, and whole grains. The human body regulates iron levels by adjusting the rate of its absorption in the digestive tract through the iron regulatory hormone, hepcidin.

There are a few disorders where this hormone production can be suppressed and it can lead to iron overload. Iron is one mineral that can be easier to overdo. So much so that accidental overdose of iron continuing products is the leading cause of fatal poisoning in children under six.

Iron overdose may happen if someone is supplementing individual iron, plus taking a multivitamin with iron. Most multivitamins don't include iron unless it specifically says with iron on the front of the bottle; something you can also look for on the supplements panel on the back. It is something worth checking. Early symptoms of iron overload can include nausea, vomiting, and stomach pain.

Iron deficiency is common, so iron supplementation is also common. If you're deficient, follow your doctor's directions and take the prescribed supplemental dose. Have follow-up blood work done to check in and reevaluate your need for supplementation. In general, unless you have iron deficiency, choose supplements without iron to prevent iron overload. Continue to consume foods rich in iron as part of a balanced diet.

Probiotics

What about probiotics? We often recommend probiotics as a foundational supplement to support gut health. When we take in probiotics, we are adding live beneficial microorganisms to the community of microbes already living within the gut with the intent of strengthening those communities of helpful microorganisms.

You might be wondering about taking too much probiotics. Probiotics don't cause toxicity in the traditional sense like vitamins can, because they don't accumulate in tissues. They seem to have more of a transient effect. You consume probiotics, they do a job that benefits you as the host, and then they eventually leave your gut.

When starting any probiotic, one piece of advice to remember is to start slowly. It can be common to experience some symptoms like bloating and gas as the gut adjusts to new probiotic bacteria. When you work individually with a dietitian, we may recommend you start with a smaller dose and work up to a higher recommended beneficial dose.

We have a great resource on our website, weightandwellness.com, to help you choose the right probiotic for you along with recommended dosages. Check out the article called “What Probiotic is Right For You?”

All in all, most people taking a high quality multivitamin mineral supplement in the suggested dosing should not have toxicity as a result. Pay attention and take caution if you are taking multiple supplements that you don't have high total amounts of overlapping vitamins and minerals.

Before starting a supplement or multiple supplements, remember to consult with a qualified healthcare provider who's part of your team, who knows your health, history, concerns, medications, and general typical diet.

Key takeaways

Now let's wrap up with some key takeaways. First, supplements should help fill gaps, not replace food. Supplementation can be beneficial to add on to support your overall health. Vitamin toxicity yes, can happen, but it is not common, especially when you're taking vitamin, mineral supplements at recommended doses.

Check to make sure your daily supplements don't largely overlap with specific vitamins and minerals. Working with a registered dietitian can be a great way to have some help and guidance in checking those levels and supplements to make sure we're not overdoing anything.

Schedule Nutrition Counseling

If you have questions, reach out to one of our offices to connect with a dietitian. Working with a registered dietitian, again, can help you navigate what supplements, including the doses can be a benefit for your individual health. Thank you for listening to this episode of Dishing Up Nutrition, “Ask a Nutritionist”. If you find this episode to be helpful, please leave a review and share it with a friend.

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As always, this podcast is for educational purposes only and is not a substitute for personalized medical advice. Thank you for listening and have a great day.