10.4. Vitamins

It has been observed that certain organic compounds are required in small amounts in our diet but their deficiency causes specific diseases. These compounds are called vitamins. Most of the vitamins cannot be synthesised in our body but plants can synthesise almost all of them, so they are considered as essential food factors. However, the bacteria of the gut can produce some of the vitamins required by us. All the vitamins are generally available in our diet. Different vitamins belong to various chemical classes and it is difficult to define them on the basis of structure. They are generally regarded as organic compounds required in the diet in small amounts to perform specific biological functions for normal maintenance of optimum growth and health of the organism.

Vitamins are vital substances that our body needs in small quantities. If we don't consume enough vitamins through our diet, we can develop diseases related to their deficiency. For example, lack of vitamin C can lead to scurvy, characterized by bleeding gums and weakness. Interestingly, while our bodies can’t produce most vitamins, plants can synthesize them. Some gut bacteria can also create certain vitamins for us. Vitamins are a diverse group of compounds, and categorizing them solely based on their chemical structure is challenging. Essentially, vitamins play crucial roles in maintaining health by facilitating various biological functions.

Think of vitamins as the tiny but indispensable ingredients in a recipe that makes a delicious dish. Without adding pepper or salt, the dish can taste bland, just as without vitamins, our body might not function efficiently. Each vitamin has its unique role, like adding specific flavors to enhance the overall taste of the meal.

Vitamins are classified into two groups depending upon their solubility in water or fat. (i) Fat soluble vitamins: Vitamins which are soluble in fat and oils but insoluble in water are kept in this group. These are vitamins A, D, E and K. They are stored in liver and adipose (fat storing) tissues. (ii) Water soluble vitamins: B group vitamins and vitamin C are soluble in water so they are grouped together. Water soluble vitamins must be supplied regularly in diet because they are readily excreted in urine and cannot be stored (except vitamin B12) in our body.

Vitamins can be categorized based on how they dissolve in liquids: fat-soluble and water-soluble. Fat-soluble vitamins (A, D, E, and K) dissolve in fatty substances and are stored in our body’s fat tissues and liver. This means we don't need to consume them daily, as our body can draw from these stores. In contrast, water-soluble vitamins, which include the B-vitamins and vitamin C, dissolve in water and cannot be easily stored. Therefore, these must be consumed regularly because excess amounts are excreted through urine. One exception is vitamin B12, which can be stored to some extent in the body.

Consider fat-soluble vitamins like a storage room filled with supplies for the long winter. You only need to check on it occasionally. On the other hand, think of water-soluble vitamins as groceries that need to be replenished often, similar to milk that spoils quickly if not used. You need to buy fresh milk regularly to ensure you have some available.

Some important vitamins, their sources and diseases caused by their deficiency are listed in Table 10.3.

Different vitamins come from various food sources, and each vitamin is linked to specific health issues if we don't get enough of it: Vitamin A from fish liver oil and carrots helps maintain healthy vision. Its deficiency can cause night blindness or xerophthalmia. Vitamin B1 (Thiamine) is found in yeast, milk, and beans, and its lack can lead to beriberi, which affects appetite and growth. Vitamin C, abundant in fruits like oranges, prevents scurvy, while vitamin D, sourced from sunlight and fish, is vital for bone health and its deficiency leads to rickets. The key takeaway is to eat a varied diet to obtain all necessary vitamins.

Imagine your body as a car that depends on specific fuel types to run smoothly. Just as a car requires various fuels (gasoline, diesel, oil) for different functions, your body needs a range of vitamins to maintain health. If the car runs low on one type of fuel, it might stop working properly, just like insufficient vitamins can lead to specific health issues.

Excess of vitamins is also harmful and vitamin pills should not be taken without the advice of a doctor.

While vitamins are essential for health, getting too much of them—especially through supplements—can lead to adverse effects. Certain vitamins can accumulate in the body, leading to toxicity. For example, too much vitamin A can result in liver damage and other health complications. Thus, it's important not to self-medicate with vitamin pills without consulting a healthcare professional.

Think of vitamins like medicine: just because a little can help you feel better, doesn't mean more is always better. Just as taking too much aspirin can cause stomach issues or bleeding, overdosing on vitamins can also harm your body. It's always wise to seek professional advice when considering supplements.

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