Vitamins and Health

Vitamins are organic, energy-free compounds that the human body requires in tiny amounts to support vital biological processes related to growth, development and disease prevention.

The human body needs 13 different types of vitamins which can be obtained from diverse animal and plant food sources, as the body lacks the full capacity to synthesise them. Vitamins are divided into two groups:

1) Fat-soluble vitamins:

– Includes 4 vitamins – A, D, E and K.

– They are not water-soluble and thus do not break down during cooking.

– Excess amounts are not excreted but stored in the liver and fatty tissues, so overconsumption can be toxic.

– They are mostly obtained through food, except vitamin D which can be synthesised in the skin through sunlight exposure, and vitamin K by bacteria in the colon.

2) Water-soluble vitamins:

– Includes 9 different vitamins – the B vitamins and vitamin C.

– They are water-soluble, so a significant amount is lost during cooking.

– Excess is excreted in urine, so overconsumption is less dangerous.

– They must be obtained daily through food as they cannot be synthesised in the body.

The Importance of Vitamins

– Play an active role in producing enzymes, hormones and other compounds needed for normal growth.

– Vital for proper body function at all life stages.

– Regulate fluid balance inside and outside body cells.

– Help prevent diseases or conditions caused by vitamin deficiencies or excess.

– Boost and strengthen the immune system.

– Some vitamins help fight inflammation and maintain nervous system health.

Some Vitamin Types and Their Sources

The variety of vitamins essential for the body can be obtained through a balanced, nutritious diet:

Vitamin A


– Supports tissue growth and repair.

– Enhances immune function for disease prevention.

– Essential for good vision, bone and mucous membrane health and skin condition.

– Acts as an antioxidant, helping prevent cancer.

Natural sources:

– Animal sources: Eggs, liver, fatty fish, fortified dairy.

– Plant sources: Leafy greens like spinach and broccoli, carrots, sweet potato, pumpkin and apricot.

Vitamin D


– Promotes bone, teeth and muscle health by regulating calcium absorption, so deficiency can cause brittle bones.

Natural sources:

– Sunlight exposure allows the skin to synthesise it.

– Fatty fish like salmon, sardines and tuna.

– Egg yolk.

– Fortified foods like cereal and milk.

Vitamin K


– Essential for blood clotting and wound healing.

– Supports heart and bone health.

Natural sources:

– Leafy greens like broccoli, and spinach.

– Legumes like beans and peas.

– Intestinal bacteria.

– Small amounts in meat and dairy.

Vitamin E


– Maintains skin and eye health by increasing vitamin A absorption.

– Helps repair damaged cells and reduce free radical damage and ageing.

– Powerful antioxidants that may help prevent cancers.

Natural sources:

– Nuts and seeds like almonds, walnuts, and peanuts.

– Whole grains.

– Fruits like avocado, apple, kiwi and mango.

– Vegetables like spinach, broccoli and tomato.

– Plant oils like olive oil.

– Liver and egg yolk.

Vitamin C


– Maintains healthy skin, blood vessels, bones, and cartilage.

– Assists wound healing and collagen production.

– Antioxidant that may prevent many cancers.

– Enhances immune function.

– Improves iron absorption.

Natural sources:

It’s important to consume vitamin C-rich foods daily since it cannot be stored in the body. Sources include:

– Citrus fruits like oranges, grapefruit, and strawberries.

– Vegetables like broccoli, green pepper, tomato, potato and cauliflower.

Vitamin B

There are several types of vitamin B:

– B1 Thiamine

– B2 Riboflavin

– B3 Niacin

– B5 Pantothenic acid

– B6 Pyridoxine

– B7 Biotin

– B9 Folic acid

– B12 Cobalamin


– Provide the body with energy.

– Help produce red blood cells.

– Maintain a healthy nervous system.

– Keep hair, skin and eyes healthy.

Natural sources:

The 8 B vitamins have similar food sources but some are richer sources of specific types. They can be obtained by eating:

– Animal sources like meat, fish, eggs and dairy.

– Leafy greens, beans and peas.

– Enriched bread and cereal.

The B vitamins are prone to damage from heat, so one should avoid cooking these foods for a prolonged time.


Vitamins play a huge role in health, and any deficiency or excess beyond needs can cause various health issues.

There are set dosages for consuming all vitamin types and exceeding these doses, especially long-term, can cause symptoms ranging from mild to severe. For instance, high doses of vitamin A may cause dizziness or headaches, while vitamin C excess can lead to digestive problems.

Similarly, inadequate intake can be problematic – vitamin D deficiency can increase the risk of brittle bones.

Most people do not need vitamin supplements, and it is best to obtain them from natural food sources by following a healthy, balanced diet.

Supplements may help some people ensure adequate nutrient intake or boost health/performance if their diet lacks variety and puts them at risk of deficiency. However, one should seek medical advice before taking supplements – doctors can provide guidance on type, dosage, duration and necessary testing, especially for those on medication, as interactions may affect drug absorption, efficacy and cause other side effects.

By: Dr. Badreyya Al-Harmi, Consultant Public Health, Emirates Public Health Association

Al Jundi

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