Vitamins are organic substances we need in tiny amounts—just milligrams or even micrograms—but without them, the body simply cannot function. They do not provide energy like carbohydrates or fats. Think of them as the oil that keeps enzymes working and metabolism running smoothly. Here is an overview of what vitamins are, where to get them, and when supplements really make sense.
What vitamins are and why you need them
Vitamins are biologically active substances found only in living things. More than 20 vitamins function in the human body, and most are associated with enzymes—many enzymes simply cannot get to work without the right vitamin acting as a coenzyme. That is why, after a winter of eating a limited range of foods, you may feel tired in spring, fall ill easily, and find your capacity for work reduced.
Historically, each newly discovered vitamin was assigned the next capital letter in the alphabet—A, B, C, and so on. Scientists now prefer chemical names, but the letters have proved hard to displace in everyday language. Interestingly, until the early 1900s, food was thought to need only protein, carbohydrates, fats, minerals, and water. Scurvy, rickets, and beriberi were known diseases, but no one had yet connected them with diet.
Fat-soluble and water-soluble vitamins
Vitamins are divided into two groups according to their solubility. Fat-soluble vitamins (A, D, E, K) are stored in the liver and fatty tissue, with reserves that can last from months to years. Water-soluble vitamins (C and the B vitamins) are not stored in significant amounts; reserves usually last only a few weeks, and any excess is excreted in urine.
This distinction has practical implications. It is almost impossible to get an excessive dose of water-soluble vitamins from food. With fat-soluble vitamins, however, the opposite is true: high-dose supplements containing these vitamins can seriously harm your health. This is why dietary guidelines also set maximum daily intakes that should not be exceeded over an extended period.
Your body can produce some vitamins itself. Gut microbiota synthesize some of the vitamin K and B vitamins you need, while vitamin A is synthesized from beta-carotene. Most vitamins, however, must come from food.
What causes hypovitaminosis
Avitaminoses—the classic diseases caused by a complete lack of a vitamin—are fortunately rare in Estonia today. More common is hypovitaminosis: an insufficient intake that does not produce a recognizable illness but gradually undermines your well-being. There are several reasons for this:
- A lack of variety in your diet—if you eat the same foods every day, you are bound to fall short of some vitamins.
- Losses during processing—when refined flour is produced, B vitamins are removed along with the bran, and more are destroyed during bread baking.
- Increased requirements—growing children, pregnant women, and breastfeeding mothers need more.
- A prolonged course of antibiotics damages the gut microbiota that synthesize vitamins.
- Liver diseases impair the absorption of fat-soluble vitamins.
- Smoking, excessive alcohol consumption, and chronic stress increase requirements and reduce absorption.
Vitamins from food or supplements
If you are healthy and eat a varied diet, you get the vitamins you need from food and do not need supplements. The reason is simple: foods never contain just one vitamin, but a whole range that work together. Vitamin C and bioflavonoids often occur together and enhance each other’s effects. Vitamin C also improves iron absorption. Vitamins from food are also cheaper than tablets.
But it is not entirely clear-cut. In spring, when carrots and cabbage stored in the cellar over winter have lost their vitamin C, you may need a supplement. The same applies during stressful periods. If your diet has been unbalanced for years—with vegetables barely making an appearance—a supplement is a temporary bridge, not a permanent solution. Before grabbing a supplement from the cupboard, though, it is worth talking to your doctor: there are plenty of options, and not all suit everyone.
How food preparation affects vitamins
How well vitamins are retained depends on how food is processed. One of the most sensitive is vitamin C, or ascorbic acid, which is broken down by the enzyme ascorbate oxidase (ascorbinase). This enzyme is very active in potatoes—by spring, their vitamin C content has more than halved. Ascorbate oxidase is less active in cabbage and swede, where losses stay at around a quarter. An apple stored over winter contains negligible amounts of vitamin C; by contrast, one medium orange meets your daily requirement.
A few practical tips to help preserve vitamins:
- Do not leave peeled and grated vegetables exposed to the air—vitamin C oxidizes quickly. Add salad dressing immediately.
- When boiling vegetables, add the pieces to water at a rolling boil. Boiling water contains little oxygen, and cooking time is shorter, preserving heat-sensitive vitamins.
- Avoid copper and iron utensils when vitamin-containing food will remain in contact with them for a long time—heavy metals break down vitamins.
- Store vegetables somewhere cool and dark; light and warmth are enemies of most vitamins.
Frequently asked questions about vitamins
Can vitamin supplements replace vegetables?
No. A tablet provides one or more individual compounds, but vegetables also contain dietary fiber, bioflavonoids and hundreds of other substances that work together. A supplement is an addition, not a replacement.
Can you overdose on vitamins?
It is virtually impossible through food. With supplements, however, you can, especially with fat-soluble vitamins (A, D, E, K) – these accumulate in your body, and excessive intake over a long period can cause serious side effects. That is precisely why recommended daily upper limits exist.
When should you consider a supplement in spring?
If you have eaten few vegetables over the winter, fresh produce is missing from your meals and you feel sluggish, a short course of vitamin C or vitamin D is a sensible option. Vitamin D is already a challenge in Estonia during the darker half of the year, as there is not enough sunlight to trigger its production. Ask your doctor or pharmacist about the dose – general promises are best avoided here.
Author: Marek Morozov
Get more vitamins here: https://turg.fitness.ee/en?view=browse&q=vitamiinid
Source: Health Board – food supplements.
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