The Role of Vitamins

Vitamins (also known as micronutrients) are essential nutrients that must be provided daily. Although needed in very small amounts, vitamins play a crucial role in human life: they are indispensable catalysts for metabolic processes in the body.

Vitamins are divided into two categories: fat-soluble vitamins (A, D, E, K) and water-soluble vitamins such as B vitamins and vitamin C.

Since the human body cannot synthesize vitamins on its own (except for converting provitamin D in the skin into vitamin D through proper sun exposure), it is essential to have a balanced diet to ensure adequate vitamin intake.

The daily vitamin requirements for the human body are minimal and vary by age. However, deficiencies can lead to disorders ranging from mild to severe and may cause various dangerous diseases. Prolonged deficiencies can affect the cognitive and physical development of children and, in severe cases, may lead to death.

Conversely, excessive vitamin intake can also harm health, leading to conditions caused by vitamin overdose.

Common Causes of Vitamin Deficiency in Children

Inadequate Nutritional Supply

• Poor Meal Quality: Meals may lack quality due to economic difficulties or a lack of knowledge about proper cooking methods.
• Spoiled Food: Eating moldy rice or stale food can lead to a deficiency in B vitamins. Overripe or improperly stored fruits and vegetables can lose vitamin C.
• Improper Food Preparation: Cooking methods that involve soaking food for too long, using excessive water, or reheating multiple times can deplete vitamins.
• Refined Foods: Foods like white bread, refined flour, and fat-free milk often lose significant vitamin content.
• Canned Foods: These often undergo sterilization processes that can reduce vitamin levels.
• Low Fat Intake: Insufficient fat in the diet can lead to deficiencies in fat-soluble vitamins like vitamin A.
• Excessive Dietary Restrictions: Children not breastfed or on overly restrictive diets may also miss essential vitamins.

Medical Conditions

• Malnutrition: Conditions such as chronic diarrhea, absorption disorders, liver, or gallbladder diseases can lead to deficiencies.

Other Causes

• Increased Body Demand:
  • Premature infants, twins, or rapidly growing children have higher vitamin needs, especially for vitamin D, which may not be met through diet alone.
  • Children on improper weight-loss diets may also experience vitamin deficiencies.
  • Lack of milk consumption can lead to inadequate vitamin intake.
  • Long-term use of certain medications (like corticosteroids, antacids, or antibiotics) can result in vitamin depletion.
  • Limited sun exposure can further contribute to deficiencies.

The Effects of Vitamin Deficiency or Excess in Children

Vitamin A
Vitamin A protects the eyes, prevents night blindness and dry eye conditions, ensures normal growth of bones and teeth, protects mucous membranes and skin, and enhances the body’s resistance to infections.

• Deficiency:
  • Dry eyes, potentially leading to permanent blindness.
  • Reduced immune function.
  • Stunted growth; prolonged deficiency in vitamin A can affect a child’s cognitive development.
• Excess:
  Vitamin A is fat-soluble and can be stored in the body. Excessive daily intake over time can cause chronic toxicity symptoms, including:
  • Headaches, fatigue, nausea, skin redness, dry and peeling skin, oral mucosal inflammation, or bone pain.
  • In young children, it can lead to increased intracranial pressure, bulging fontanelle, headaches, and seizures.
  • Pregnant women in the first trimester taking high doses of vitamin A may risk birth defects (e.g., cleft palate, cardiovascular anomalies, central nervous system issues). Therefore, pregnant women must consult a specialist before using vitamin A supplements.
• Rich Sources:
  Found mainly in animal products: liver, meat, eggs, full-fat dairy products (milk, cream, butter).
  Plant sources include yellow/red fruits and vegetables (tomatoes, carrots, ripe papaya), dark green leafy vegetables (amaranth, water spinach), and certain fortified oils.

Vitamin C
Vitamin C boosts the immune system and helps wounds heal faster when tissues are saturated with it.

• Deficiency:
  Causes may include lack of breast milk, insufficient intake of fruits and vegetables, overcooked foods, or gastrointestinal infections. Vitamin C deficiency typically occurs in children aged 6 months to 2 years, presenting as subcutaneous and mucosal bleeding (e.g., bleeding gums, swollen gums, nosebleeds, poor-quality dental enamel, or tooth decay).
• Excess:
  Can lead to metabolic acidosis and increase the risk of kidney stones. High doses of vitamin C over prolonged periods can cause a dependency syndrome.
• Rich Sources:
  Fresh fruits and vegetables such as oranges, lemons, tangerines, grapefruits, tomatoes, broccoli, and mangoes are excellent sources of vitamin C.

Vitamin D
Vitamin D helps the body effectively use calcium and phosphorus to form and maintain strong bones and teeth.

• Deficiency:
  For calcium to be absorbed and utilized properly, adequate vitamin D is necessary. Without it, children may suffer from rickets, even with sufficient calcium intake. Children raised in poorly lit, cramped conditions or who do not get enough sunlight are at higher risk for rickets and delayed tooth eruption.
• Excess:
  Vitamin D overdose is rare due to limited dietary sources. For healthy infants under one year receiving formula, supplementation should not exceed 400 IU per day. Excessive long-term vitamin D intake can lead to toxicity, increasing calcium levels in the blood and urine, causing anorexia, nausea, vomiting, thirst, muscle weakness, disorientation, fatigue, and potentially kidney damage or death.
• Rich Sources:
  Natural sources are limited. However, cod liver oil (especially from fatty fish like mackerel and herring) and eggs are notable. Most vitamin D is synthesized in the body from precursors under sunlight.

Vitamin B1 (Thiamine)

• Deficiency:
  Symptoms include indigestion, diarrhea, poor circulation, and anxiety, leading to beriberi.
• Excess:
  Rare.
• Rich Sources:
  Found in rice bran, whole grains, oats, meat, liver, and heart. Avoid overcooking vegetables and grains, as high temperatures can destroy vitamin B1.

Vitamin PP (B3)

• Deficiency:
  Common in children consuming porridge, corn, or those in shelters with inadequate diets, leading to chronic diarrhea, oral and tongue inflammation, insomnia, and lethargy.
• Excess:
  Rare.
• Rich Sources:
  Abundant in foods, particularly yeast products. Meat and fish are also good sources, along with liver, whole grains, nuts, and legumes.

Vitamin B6

• Deficiency:
  Symptoms include hair loss, acne, red eyes, blurred vision, fatigue, insomnia, and slow wound healing.
• Excess:
  Overuse can lead to sensory neuropathy.
• Rich Sources:
  Found in soybeans, cabbage, eggs, and peanuts.

Vitamin B12
Vitamin B12 regulates protein metabolism, enhances red blood cell production, and lowers cholesterol. It also has anti-allergic and pain-relieving effects.

• Deficiency:
  Symptoms include headaches, poor appetite, shortness of breath, constipation, poor concentration, and forgetfulness, affecting blood production and the nervous system.
• Excess:
  Overuse can lead to thyroid hyperplasia, excessive red blood cell production, and cardiomyopathy, with potential side effects like nausea, dizziness, and urticaria.
• Rich Sources:
  Found in liver, beef, eggs, cheese, milk, and kidneys.

When to Supplement Vitamins for Children

Typically, healthy children who are breastfed and have a balanced diet do not need additional vitamin supplements. However, if there are concerns about diet quality—even if a child is of appropriate height and weight—it may be necessary to supplement vitamins. Doctors may recommend vitamin supplementation for some children. In cases of obesity, a low-fat diet may not provide enough fat-soluble vitamins (A, D, E, K), so supplementation is often advised.

Children who are malnourished, underweight, or recovering from illness (infections, asthma, diarrhea) should definitely receive vitamin supplements.

While obtaining vitamins through food is essential, taking multivitamin supplements can be helpful when deficiencies are identified. However, the best source is always natural vitamins.

Minimizing Vitamin Loss in Food Preparation

• Avoid using excessively hot water for mixing milk or powder; consume immediately after preparation. Fruits lose vitamins quickly once peeled, cut, or juiced.
• Juice should be prepared and packaged only when needed. Spices containing vitamins should only be added after cooking.

Precautions to Avoid Excess Vitamin Supplementation in Children

Among vitamins, A and D should not be taken in excess, as they can accumulate in the body and cause toxicity. High doses of vitamin C (over 1g/day) can lead to diarrhea, gastrointestinal ulcers, and kidney stones with long-term use.

To avoid the consequences of incorrect vitamin use, it is crucial to adhere to the principle: do not take vitamins unless there is a deficiency; they should not be considered “tonics” for health. Therefore, if there are health concerns (poor appetite, difficulty sleeping, lethargy, dull skin), the best approach is to consult a healthcare professional. They will examine the child and run necessary tests to determine health status and provide appropriate guidance. Avoid self-medicating with vitamins, especially high-dose or combination supplements taken for extended periods.