Vitamins are micronutrients that your body needs to support its normal functions. They play key roles in your growth and development, immune health, and wellbeing. You need a certain amount of vitamins to support these functions, so it can be helpful to be aware of food sources of vitamins.
Vitamins can also be found in dietary supplements that can help fill in gaps in your nutrition. However, it is possible to overdo it on vitamins.
Let’s review the specifics on vitamins and discuss how to use them safely to prevent getting too much.
Vitamins can be divided into two main categories: fat-soluble vitamins and water-soluble vitamins.
Fat-soluble vitamins need fat to be absorbed. They include vitamins A, D, E, and K. Because they are stored by your body, there can be concern for taking too much.
Water-soluble vitamins need to dissolve in water before being absorbed by your body, so they are not stored. They include B vitamins and vitamin C.
Water-soluble vitamins that are not used by your body are lost in the urine. But this does not mean you can take high doses without any issues. We will discuss this later on, but let’s first get to know some of the key fat-soluble and water-soluble vitamins.
Vitamin A Vitamin A is needed for the normal functions of many systems in your body, including your immune and cardiovascular system.
Vitamin A is found in foods as two main types: retinoids and carotenoids. Retinoids are found in animal products and carotenoids are found in plants. Sources of retinoids include dairy, eggs and liver.
You may know that carrots are good sources of a carotenoid called beta-carotene (carotene sounds a lot like carrots, right?). But other foods like spinach and sweet potatoes are also rich in beta-carotene.
The daily recommended amount of vitamin A is 700-900 mcg RAE (micrograms of retinol activity units).
Vitamin D Vitamin D is important for healthy bone growth and your immune function. It also helps your body absorb calcium.
Your body makes vitamin D in response to sun exposure on the skin. But cold temperatures and long working hours can limit sun exposure. Older people and those with dark-colored skin do not make as much vitamin D.
Vitamin D is naturally found in fatty fish and fish liver oil. Beyond that, the food supply is fortified with vitamin D from milk and breakfast cereals.
It’s recommended that adults ages 19-70 get 15 mcg (600 IU) of vitamin D per day and adults 71 and older get 20 mcg (800 IU) per day.
Vitamin E Vitamin E is an antioxidant that can help protect your cells. It also supports your immune system and the health of your blood vessels.
Vitamin E can be found in wheat germ and sunflower and safflower oils. Nuts and seeds, especially almonds and sunflower seeds, also provide vitamin E in the diet. Vitamin E is sometimes added to foods like breakfast cereals and fruit juices.
The recommended intake of vitamin E for adults is 15 mg per day.
Vitamin K Vitamin K supports normal blood clotting and healthy bones. It’s mostly found in green leafy vegetables like spinach, kale, and broccoli.
The recommended intake of vitamin K for adults is 90-120 mcg per day.
B Vitamins B vitamins such as folate, riboflavin, and B12 support your nervous system and are needed to make energy from foods.
B vitamins can be found in a variety of plant and animal sources. It should be noted that animal products are the primary natural food source of vitamin B12. Therefore, those following a vegan diet need to get vitamin B12 from fortified foods and/or dietary supplements. Those who eat a vegetarian diet may also be at risk for B12 deficiency, depending on the specifics of the diet.
The daily needs for B vitamins varies depending on the specific vitamin.
Vitamin C Vitamin C (ascorbic acid) is an antioxidant that can help protect your cells from damage. It can support the health of your skin and connective tissue because vitamin C helps the body make collagen.
Vitamin C is found in citrus fruits (such as oranges), kiwi, strawberries, bell peppers, and broccoli. Heat can lower the amount of vitamin C in foods, so including raw fruits and vegetables in the diet can help meet needs.
It’s recommended to get 75-90 mg of vitamin C per day.
As you may have noticed, eating a balanced diet that is full of a variety of foods is the best way to meet your vitamin needs. But what about overdosing on vitamins? It would be very difficult to overdose on vitamins from foods. However, vitamins from dietary supplements can potentially be an issue if you take too much.
Yes, you can overdose on vitamins. But some vitamins pose more of a risk than others. Let’s explore this.
As we discussed, fat-soluble vitamins can be stored in the body so there is a bigger risk of getting too much as compared to water-soluble vitamins.
Multiple vitamin overdose is possible if someone were to take well above the recommended serving of a multivitamin. Multivitamins contain vitamins, but they also contain minerals. Iron is one mineral to be aware of because it can be harmful if too much is taken.
Signs and symptoms of a vitamin overdose are not always clear. They can range from bleeding issues, to digestive upset, to neurological symptoms. Therefore, it’s essential to talk to your healthcare provider about any new symptoms or health concerns you are experiencing.
Fat-soluble vitamin overdose is possible, especially from supplements or medications.
Vitamin A toxicity can occur from high doses of retinoids. Whereas beta-carotene does not pose the same risk for reproductive toxicity. Taking high doses of retinoids can cause severe headache, blurred vision, nausea, dizziness, aching muscles, and coordination problems. In the long-term, toxicity can lead to dry skin, painful muscles and joints, fatigue, liver problems, and poor mood.
Most people are deficient in vitamin D so supplementing can be helpful. Very high levels of vitamin D however can cause a variety of symptoms including nausea, vomiting, and excessive thirst. And in extreme cases it can also contribute to potential issues with other organ systems. Be sure to monitor your vitamin D levels every so often when taking high doses to treat a deficiency.
Excessive intake of vitamin E or vitamin K can thin the blood and contribute to bleeding issues especially when taking certain medications. It is essential to talk to your healthcare provider about your intake of all over the counter supplements when taking prescribed medication.
Water-soluble vitamin overdose is less likely since your body gets rid of what it does not use in the urine. But they can cause some unpleasant symptoms at excessive doses.
For example, there have been some reports of high doses of vitamin C resulting in digestive discomfort such as nausea, diarrhea, and stomach cramps.
Niacin (B3) may cause flushing, rash, headaches, dizziness, or changes in blood pressure at high doses. At pharmacologic doses, it can cause liver issues that range from mild elevations in liver enzymes to other health issues.
Always talk to your doctor about new vitamins and supplements being used over the counter especially if you are taking prescribed medications. Your prescribing physician or pharmacist can advise you about any potential interactions.
Contact poison control right away if a child accidentally ingests supplements meant for an adult. You should always make sure that your vitamins and medications are kept out of reach of children. You should also keep supplements away from pets, as certain ingredients may be toxic to them.
If you believe you’ve taken too much of a supplement or a medication, contact poison control.
To safely take vitamins, follow the label instructions exactly as they appear on the bottle or follow the directions provided by your healthcare provider. More vitamins is not always better!
Always talk to your healthcare provider before starting any new supplements and make sure to inform them of all the medications and supplements you currently take at each visit.
While it is possible to overdose on vitamins, the risk is greatest from taking too much in the form of dietary supplements or medications. Stay safe! Talk to your healthcare provider about the vitamin doses that are right for you and always follow label directions.