Almost everyone knows that eating more vegetables and fruits can supplement vitamins. However, some people do not like fruits and vegetables, or are too busy to ensure a balanced diet, so "vitamin supplements" have become a new choice.

    Can vitamin dietary supplements replace the nutrition in fruits and vegetables?

Experts will interpret the difference between vitamin supplements and fresh fruits and vegetables, and tell you how to take different vitamins.

Supplements cannot completely replace fruits and vegetables

Vitamin has very little content in human body, but it plays an important role in growth, development, metabolism and other processes. However, there is a big difference between taking vitamin tablets alone and taking supplements through food.

  Vegetables and fruits contain more than vitamins

Each kind of fruit and vegetable contains hundreds of ingredients, which will cooperate and protect each other. It is difficult for vitamin supplements with single ingredients to achieve the health care effect of natural food.

Rich dietary fiber. The dietary fiber contained in fruits and vegetables can promote intestinal health, prevent constipation and delay the absorption of blood sugar.

Rich in inorganic salts. Calcium, phosphorus, iron, potassium, sodium and other inorganic salts can maintain cell morphology and function, maintain life activities of organisms, and maintain cell osmotic pressure and acid-base balance.

Organic acids. The content of fruit can stimulate human digestive glands, increase appetite and help digestion.

Various enzymes, fungicides and physiologically active ingredients with special functions in vegetables and fruits, as well as terpenoids, polyphenols, plant sterols and other phytochemicals, play an important role in maintaining human health.

It is suggested to have diversified food and balanced nutrition on weekdays. According to the Dietary Guidelines for Chinese Residents (2022), each person should eat at least 300g of vegetables and 200-350g of fresh fruits every day.

  May increase physical burden

For healthy people, blind or excessive supplementation of certain nutrients may cause or aggravate metabolic disorder of other nutrients and increase body burden.

1. Large intake of liver, cod liver oil or vitamin A supplements can lead to abnormal bone growth, even osteoporosis, and may also cause liver damage.

2. Excessive vitamin C supplementation will lead to nausea and diarrhea, which may increase the risk of kidney stones for people with renal dysfunction, gout patients and people at high risk of kidney stones.

3. Excessive intake of cod liver oil or vitamin D supplements may lead to excessive blood calcium, promoting kidney stones, vascular sclerosis, etc.

4. Vitamin E is less toxic, and large intake can cause coagulation dysfunction, liver fat accumulation and decline of immune system function.

Food is the priority of vitamins

For the general population, fresh vegetables and fruits are the preferred choice for vitamin supplementation. Common vitamins can be taken from the following foods.

   Vitamin A eye protection and anti infection

It mainly comes from animal liver, milk, poultry eggs, and dark green or red, yellow and orange fruits and vegetables with high carotenoid content.

   B vitamins can prevent many diseases

B vitamins, including vitamin B1, vitamin B2, vitamin B12, niacin, folic acid, etc., are indispensable substances to promote metabolism in the body.

Vitamin B1 can be supplemented by eating more coarse grains, beans, potatoes and some animal viscera.

Vitamin B2 is widely found in milk, egg yolks, dark green vegetables, grains, fish and meat, and nuts.

Nicotinic acid (vitamin B3) mainly comes from plant seeds and animal foods rich in high-quality protein, especially fish and eggs.

Folic acid (vitamin B9) is an essential vitamin for pregnancy preparation. Its food sources are wide, such as green leafy vegetables, beans, fruits, etc.

Vitamin B12 is a kind of vitamin that vegetarians and the elderly are easy to lack. It exists in animal food, fermented food and fungus food.

Vitamin C Anti aging

It mainly exists in fresh vegetables and fruits, and the content of leaf vegetables is usually higher than that of rhizomes. Foods rich in vitamin C should be eaten raw if possible, such as fruits, onions, lettuce, etc. If the gastrointestinal function is not good, avoid eating raw vegetables.

Vitamin D promotes bone development

The source of vitamin D in food is not rich, only fish liver oil, liver, full fat milk, egg yolk, fatty fish and a few other sources, and more sun exposure is the best source of sufficient vitamin D.

  Vitamin E enhances resistance

Food sources are extensive, and can be supplemented by taking vegetable oil and nuts. As long as you eat a normal diet at ordinary times, you should ensure that you take in a certain amount of oil every day, such as 20-30g cooking oil, and eat an appropriate amount of nuts, usually without vitamin E.

  Who needs additional supplement

For specific people who cannot have a balanced diet or live irregularly, vitamin supplements should be used to ensure their daily intake, but they should be supplemented scientifically and therapeutically under the guidance of professionals.

  Pregnant women

Folic acid is especially important for pregnant women. Especially in the first few weeks of pregnancy, if the fetus does not get enough folic acid, it may have neural tube defects such as spina bifida, which may lead to anemia in pregnant women and fetuses in the late pregnancy.

It is recommended that women start taking folic acid supplements every day at least 3 months before pregnancy or when they may be pregnant.

   People with impaired vision

Vitamin A has a great impact on vision. If the intake is insufficient, the ability to see things at night will become worse, and even suffer from night blindness and dry eye. Vitamin A supplementation has a certain protective effect on vision.

Osteoporosis

Both vitamin C and vitamin D play an important role in promoting collagen synthesis and limiting bone absorption. Vitamin D deficiency will lead to abnormal minerals in bones and teeth, resulting in osteomalacia and osteoporosis.

It is suggested that people with osteoporosis should take these two vitamins every day to reduce the risk of fracture.

   Iron deficiency anemia

The trivalent iron in plant food cannot be directly absorbed by the human body. Vitamin C can convert it into divalent iron that can be directly absorbed. Vitamin B12 deficiency can also lead to megaloblastic anemia, nervous system damage and cardiovascular disease.

Vitamin supplementation is very important to improve iron deficiency anemia, and this kind of people should pay special attention to it. ▲

Experts interviewed

Liu Ailing, Researcher, Institute of Nutrition and Health, China Center for Disease Control and Prevention

Jing Hao, Professor, School of Food Science and Nutrition Engineering, China Agricultural University