6 Symptoms may include kidney stones, nausea, recurrent vomiting, constipation, excessive thirst, excessive urination, confusion and weight loss. Taking high doses has also been linked to cancer risk, heart problems, and an increased risk of bone fractures.
Dwyer says vitamin D, calcium, and folic acid are three nutrients you may get too much of, especially through supplements. Adults who regularly far exceed the 4,000 international units (IUs) daily safe upper limit for vitamin D might may end up with serious heart problems.
Watch out for these fat-soluble vitamins: A, E and K
Vitamin A is a fat-soluble nutrient that is naturally present in many foods, like beef, eggs and many fruits and vegetables. An overdose of this vitamin can lead to problems with confusion, hair loss, liver damage and bone loss.
Being on numerous supplements means you're at risk of actually overdosing on a certain vitamin or mineral. For example, if your diet is already very high in iron,an additional supplement might actually push you over the necessary threshold. Excess iron can lead to nausea, stomach cramps and diarrhoea.
You can—but it's probably not a good idea. For some supplements, optimal absorption can depend on the time of day taken. Not only that—taking certain vitamins, minerals, or other supplements together can also reduce absorption and may result in adverse interactions, which can be harmful to your health.
"It may seem like common sense to be taking multivitamins, but there actually isn't much evidence that a daily cocktail of essential vitamins and minerals actually delivers what you expect." Most studies have found no significant benefit from taking a daily multivitamin to protect the brain or heart or prevent cancer.
Too much vitamin D may harm bones, not help - Harvard Health.
But excessive amounts can lead to fatigue, weakness, nausea, headache and diarrhea. Water-soluble vitamins usually don't cause problems, but in huge doses they can.
Extra amounts of water-soluble vitamins are typically excreted. The fat-soluble vitamins A and D are the most likely to cause toxicity symptoms if you consume them in high amounts.
Combining multiple supplements or taking higher-than-recommended doses can increase the risk that they can cause harm, said Kitchin. "You really can't get toxic doses of nutrients through food, but you can absolutely get toxic doses through supplements," Kitchin said.
When taken in excess, water-soluble vitamins are removed from the body through urine. Vitamins A, D, E, and K, the fat-soluble vitamins, bind to fat in the stomach and are then stored in fatty tissues and the liver.
Symptoms of Vitamin D Excess
Early symptoms of vitamin D toxicity are loss of appetite, nausea, and vomiting, followed by weakness, nervousness, and high blood pressure. Because the calcium level is high, calcium may be deposited throughout the body, particularly in the kidneys, blood vessels, lungs, and heart.
What's more, taking too much vitamin D can also negatively impact our health as well as our joint pain because our body simply can't cope! If toxic levels of vitamin D build up in the body it can interfere with your body's absorption of calcium.
The effect of equivalent oral doses of vitamin D3 600 IU/day, 4200 IU/week and 18,000 IU/month on vitamin D status was compared in a randomized clinical trial in nursing home residents. A daily dose was more effective than a weekly dose, and a monthly dose was the least effective.
When taken by mouth: Fish oil is likely safe for most people in doses of 3 grams or less daily. Taking more than 3 grams daily might increase the chance of bleeding. Fish oil side effects include heartburn, loose stools, and nosebleeds. Taking fish oil supplements with meals or freezing them can reduce these issues.
There are a few types of these nutrients, and they're all good for your body. But three of them -- vitamins B6, B12, and folic acid -- are especially important. Vitamin B6 is also known as pyridoxine. You need it to keep your brain working well and to help your body change food into energy, which is called metabolism.
Neil Levin, a clinical nutritionist at NOW Foods, agrees that morning is best for multivitamins and any B vitamins. “Multivitamins tend to do best when taken earlier in the day, as the B vitamins in them might stimulate metabolism and brain function too much for a relaxing evening or before bed,” Levin says.
B vitamins work together (such as in a B complex supplement that contains B12, folate, B6, etc.), so they can/should be taken together. Vitamin C and iron (C helps the body absorb more iron, from both foods and supplements) Vitamin K and calcium (both support skeletal and heart health)
Yes! You can and should take magnesium and vitamin D together. In fact, the bioavailability of vitamin D largely relies on magnesium. Also, many nutrients wouldn't work efficiently without magnesium, further highlighting the importance of this mineral!
Vitamin C (ascorbic acid) supplements.
Taking vitamin B-12 with vitamin C might reduce the available amount of vitamin B-12 in your body. To avoid this interaction, take vitamin C two or more hours after taking a vitamin B-12 supplement.
Vitamin C and B12
According to Dr. Airey, some studies have shown that Vitamin C could break down Vitamin B12 in your digestive tract, reducing your B12 absorption. As a result, he says you want to wait at least two hours before taking Vitamin C with your Vitamin B12.