Do Certain Medical Conditions Require Lower Vitamin Doses?

Vitamins are organic compounds that the body needs in small amounts for various metabolic processes.

Vitamin supplements

cannot replace a healthy diet, and an imbalance of macronutrients (proteins, carbohydrates, fats) or micronutrients (vitamins and minerals) can lead to serious malnutrition diseases such as marasmus and kwashiorkor. Food is a complex source of vitamins, minerals, and phytochemicals (plant chemicals) that work together to provide the necessary nutrients. If you need to supplement your diet, your doctor or pharmacist can tell you which supplements and doses are safe for you.

The effects of severe malnutrition, such as blindness due to vitamin A deficiency, soft bones due to vitamin D deficiency, and stunted growth due to protein-energy malnutrition in children, may not be reversible even after rehabilitation. However, there is no evidence that taking large doses of any vitamin can stop or reverse the effects of aging. People with restrictive diets, such as vegetarians, those with certain medical conditions, and older adults may need to take a supplement. An excessive and chronic amount of free radicals in the body causes a condition called oxidative stress, which can damage cells and cause chronic diseases.

Consuming enough of the necessary vitamins and minerals is an essential part of a balanced diet. The best known are vitamin C, vitamin E, beta-carotene and other related carotenoids, along with the minerals selenium and manganese. Taking megadoses of certain vitamins is commonly believed to act as a medication to cure or prevent certain ailments. Look for a supplement that contains the vitamin or mineral you need without a lot of other unnecessary ingredients.

Excessive consumption of some vitamins and minerals can be harmful, and you may be paying for supplements you don't need. In general, excessive consumption of minerals or vitamins is due to the excessive intake of a certain micronutrient through the use of multivitamins or supplements. Randomized placebo-controlled trials offer little evidence that the intake of vitamin C, vitamin E, beta-carotene, or other individual antioxidants provides substantial protection against heart disease, cancer, or other chronic conditions. A simple analysis of vitamins and nutrition in blood or urine can help determine what micronutrients a person is lacking.

In some cases, medical conditions may require lower doses of vitamins beyond what can be obtained through diet or lifestyle changes alone. For example, people with kidney disease may need to limit their intake of certain vitamins because their kidneys cannot process them efficiently. People with diabetes may need to adjust their intake of certain vitamins because they are more prone to deficiencies due to their condition. It is important for individuals to speak with their doctor before taking any supplements or making any changes to their diet.

Your doctor can help you determine if you need additional vitamins or minerals beyond what you can get from your diet and lifestyle changes alone.