According to a poll by the American Osteopathic Association (AOA) published in 2019, 86% of Americans take vitamins or supplements. That result is not too surprising, but it highlights the need for education about risks and benefits for supplementing with vitamins. For benefits of supplementation I will leave that for you to discuss with your doctor based on your unique lab measurements and medical condition.
Today we will focus on the risks and symptoms of taking vitamins as they relate to overconsumption; a condition called hypervitaminosis. While it is not common to overdose on vitamins it certainly does happen and can have a profound negative impact on your health.
Vitamins can be divided into two categories; fat soluble and water soluble. Fat-soluble vitamins get stored in your body inside fat cells and provide the biggest risk for toxicity due to over supplementation. The highest-risk fat soluble vitamins are D, A and E. Vitamin K is also a fat-soluble vitamin, but in real world application overdose is not seen. Some water soluble vitamins pose a risk for toxicity as well and most notably those are vitamins C and B6. Water soluble vitamins do not get stored in the body like fat soluble vitamins, they get eliminated out of the body through the urine. Also, we will mention one mineral (Zinc) that may pose a threat.
Vitamin D
Most of us require supplementation with Vitamin D due to lifestyle and genetic factors, however that does not mean everyone should supplement with Vitamin D. Too much Vitamin D can cause the body to absorb too much calcium in the gut. This may lead to a host of problems such as nausea, vomiting, abdominal pain, muscle weakness, increased urination, confusion, bone pain and even kidney stones. Whew! That is a lot of ailments!
Vitamin A
Those who consume too much vitamin A can develop hair loss, dry skin, headache, nausea, organ damage or even coma. Bonus fact; Vitamin A supplementation over 10,000 IUs daily while pregnant can cause harm to the developing fetus.
Vitamin E
Symptoms of toxicity include easy bruising and bleeding, nausea, diarrhea, fatigue and muscle weakness. Also, some studies have indicated increased all-cause-mortality (death) with taking more than 400 IUs daily.
Vitamin C
While it is tough to overdose on Vitamin C; it does happen and causes diarrhea, nausea, stomach cramps and increased risk of kidney stones. It can also cause iron accumulation in your organs if done over a long period of time.
Vitamin B6
Toxicity from too much B6 taken chronically has been shown to cause permanent nerve damage. Short-term toxicity usually causes nausea, heartburn, skin lesions and sensitivity to light.
Zinc
Zinc is a mineral that is essential for multiple functions in the body. It is also a useful tool during cold and flu season and perhaps to fight COVID-19 (theoretically), but if taken in mega doses for too long, it can cause nausea and vomiting, abdominal pain, lethargy and fatigue. Interestingly, zinc and copper need to have a proper ratio in the body. The signs of zinc overload are actually from copper deficiency if the two minerals become imbalanced.
As we discovered, it can be dangerous to take too many vitamins. As a rule, a vitamin supplement is exactly that; a supplement to the nutrient intake from food in your diet. Focus on eating a wide variety of colorful vegetables and fruits to cover the majority of your vitamin needs. Vitamins are meant to fill in gaps and replace deficiencies or account for personal genetic risks that have been uncovered.