Vitamin A is the name given to a group of fat-soluble retinoids. It is an essential vitamin for maintaining healthy vision, fertility, supporting immune functions, and the formation and maintenance of the heart, lungs, kidneys, and other organs. Vitamin A can also act as a hormone within the body. The main types of Vitamin A include:
Preformed Vitamin A (retinol and retinyl esters), obtained from animal sources.
Provitamin A carotenoids, with beta-carotene being the most important, obtained from plant sources.
Sources of Vitamin A
Vitamin A can be obtained from both animal and plant sources. Foods rich in natural vitamin A include:
Fortified breakfast cereals
Orange and yellow vegetables and fruits such as pumpkin, carrots, squash, red peppers, and sweet potatoes
Fish oil
Eggs
Liver
Legumes, especially lentils and beans
Milk and cheese
Dark green leafy vegetables like spinach and broccoli
Organ meats such as liver
Fatty fish like tuna
Health Benefits of Vitamin A
Vitamin A offers numerous health benefits, including:
Diabetes management: Retinoic acid, derived from vitamin A, helps regulate blood sugar levels.
Cancer prevention: Adequate intake of vitamin A from plant sources is linked to a lower risk of cancers such as colon cancer; however, beta-carotene supplements have not shown the same effect.
Eye health: Vitamin A is vital for protecting against night blindness and age-related macular degeneration (AMD), a leading cause of vision loss. Antioxidant carotenoids may help prevent oxidative stress involved in AMD.
Reducing measles symptoms: Measles is a leading cause of death in developing countries; vitamin A deficiency increases disease severity. Vitamin A supplementation is recommended for children over one year old in affected areas.
Skin health: Vitamin A boosts natural oil production, keeping skin and hair moisturized, helps reduce acne by regulating oil secretion, and prevents follicular hyperkeratosis (thickening and dryness of the skin).
Immune function: Vitamin A strengthens immune barriers in the eyes, lungs, intestines, and reproductive organs and aids white blood cell production.
Bone health: It is essential for bone growth and maintenance, especially with aging.
Growth and reproduction: Vitamin A supports reproductive health in both men and women and promotes normal fetal development during pregnancy. However, excessive intake during pregnancy may cause birth defects.
Risks of Vitamin A Deficiency
Vitamin A deficiency can affect various body functions, leading to:
Increased risk of infections, especially respiratory and gastrointestinal.
Fertility issues.
Delayed growth in children.
Night blindness.
Follicular hyperkeratosis (dry, thickened skin).
Higher risk of bone fractures.
Recommended Daily Intake of Vitamin A
Vitamin A daily requirements vary by age and condition:
Adults (14+ years):
Females: 700 mcg/day (1,300 mcg/day during pregnancy and breastfeeding)
Males: 900 mcg/day
Children:
1–3 years: 300 mcg/day
4–8 years: 400 mcg/day
9–13 years: 600 mcg/day
Infants:
0–6 months: 400 mcg/day
7–12 months: 500 mcg/day
Groups at Risk of Vitamin A Deficiency
Infants and young children in developing countries: Breast milk often lacks sufficient vitamin A for infants in the first six months, and deficient mothers produce low-vitamin-A milk, necessitating supplementation.
Premature infants: They have low liver vitamin A stores at birth, increasing risk of chronic lung, eye, and digestive diseases.
People with cystic fibrosis: Due to pancreatic insufficiency, they have difficulty absorbing fats and vitamin A, but symptoms can be managed with treatment and supplements.
Pregnant and breastfeeding women in developing countries: They need higher vitamin A levels for fetal growth and metabolic support; deficiency leads to increased disease risk and mortality.
Risks of Vitamin A Overconsumption
Excess vitamin A can be toxic and may cause:
Brittle nails
Hair loss
Vision changes, including double vision in young children
Increased scalp oiliness
Birth defects in pregnant women
Vomiting
Soft spots in infants’ skulls
Drowsiness and fatigue
Nausea
Skin changes such as cracking, yellowing, itching, and sun sensitivity
Liver damage
Headaches
Gum disease
Loss of appetite
Dizziness
Difficulty gaining weight
Bulging fontanelle in infants
Certain acne medications like isotretinoin are vitamin A derivatives; people using these should avoid excess vitamin A intake. Generally, a healthy diet provides adequate vitamin A, so supplements are usually unnecessary
Al-Mustaqbal University The First University In Iraq
Goal 3 of the Sustainable Development Goals: Good Health and Well-being