The vitamins are important for the functioning of the human body. Vitamin deficiencies can cause adverse health effects. However, if you have the habit of using vitamin supplements to treat any vitamin deficiency, you may want to stick to the limit prescribed by your doctor. Too much of anything is not good for your health; this is true even with nutrients such as vitamins. Let’s examine the recommended intake of certain vitamins and the negative impact on the human body when an individual exceeds the limit.
1. Vitamin A:
The vitamin A is a group of fat – soluble vitamins. It is involved in immune function, vision, reproduction and cellular communication.
“Optimum amounts of this vitamin can be received through the diet”.
Sources of vitamin A include dairy products, liver, fish, fortified cereals and vegetables such as carrots, broccoli, melon and squash.
Recommended intake: The recommended dietary amounts for vitamin A are given as micrograms (mcg) of retinol activity equivalents (SAR). The recommended intake of vitamin A in adult men is 900 mcg RAE, while in adult women the intake is 700 mcg RAE. The maximum tolerable intake of vitamin A in adults is 3000 mcg RAE.
Side Effects of Excess Vitamin A:
Vitamin A is fat soluble and the body stores excess vitamins in the liver and levels can increase over time. Although diets provide vitamin A, the side effects of vitamin A are usually observed when taken in the form of supplements. Chronic intake of excess vitamin A may result in the following:
- Increased intracranial pressure
- Skin irritation
- Joint and bone pain
Some studies have reported that excessive vitamin A supplementation can also cause hair loss.
2. Vitamin C:
The vitamin C, also known as ascorbic acid, is water – soluble nutrient found in foods. They act as antioxidants in the body and fight free radicals that are harmful to the body. Vitamin C also plays a role in the production of collagen – protein that helps maintain skin elasticity and heals wounds. Vitamin C is also important as it helps in the absorption of iron. Some sources of vitamin C include citrus fruits such as oranges and tangerines and vegetables such as broccoli and tomatoes.
Recommended intake: The recommended intake of vitamin C for adult men is 90 mg, while for adult women it is 75 mg. People who smoke require 35 mg more than the recommended intake mentioned. The tolerable upper limit of vitamin C in adults is 2000 mg.
Side Effects of Excess Vitamin C:
People should get most of their vitamin C from the diet. However, some can obtain it through supplements and this can cause an imbalance, usually an excess of vitamin C in the body. Taking too much vitamin C can cause the following side effects:
- Stomach cramps
- In individuals suffering from hemochromatosis (a condition that causes the body to store too much iron), excess vitamin C can worsen iron overload and damage tissues.
3. Vitamin D:
The vitamin D or vitamin promotes the sun calcium absorption in the intestine and is also important for bone strength and growth. It is also required for immune function and to reduce inflammation. Unfortunately, very few food sources contain vitamin D. Some sources include fatty fish meat such as salmon, tuna and fish liver and mackerel oils.
Recommended intake: The recommended intake of vitamin D for adult men and women is the same, that is, 15 mcg. The maximum tolerable intake of vitamin D is 100 mcg.
Side Effects of Excess Vitamin D:
Excessive exposure to the sun cannot result in vitamin D toxicity. Side effects are experienced due to excess supplements. The side effects of excess vitamin D are as follows
- Cardiac arrhythmias
- Vascular and tissue calcification due to excess calcium in the blood
4. Vitamin E:
The vitamin E is another nutrient which behaves as an antioxidant and fights free radicals that can cause cardiovascular disease and even cancer. They are available in foods such as nuts, seeds, vegetable oils, green leafy vegetables and fortified cereals.
Recommended intake: The recommended intake of vitamin E in both men and adult women is 15 mg. The tolerable upper intake of the vitamin is 1000 mg for adults.
Side Effects of Excess Vitamin E:
Adverse effects of excess vitamin E through supplements have shown that it can cause bleeding and interrupt blood clotting. However, these are reports of animal studies and, therefore, more research is required if this also applies to humans.
5. Vitamin K:
The Vitamin K is an essential nutrient that helps bone health and heart. It is one of the essential nutrients for bone formation and blood clotting. There are two types of vitamin K: vitamin K1 and vitamin K2. The first is in vegetables, especially in green leafy vegetables, vegetable oils and some fruits, while the second is in dairy products.
Recommended intake: The recommended intake of vitamin K for adult men is 120 mcg, while for women it is 90 mcg. Vitamin K may be one of the safest nutrients, since the Food and Nutrition Committee has not established any side effects of excess vitamin K due to its low toxicity potential.
Therefore, it is important to provide your body with essential nutrients through a balanced diet. If there is a need for supplements, be sure to take them under the supervision of a doctor. Do not use supplements without consulting a doctor.