Vitamin A is one of the most beneficial substances for healthy skin and hair. The lack of retinol is associated not only with impaired vision at night but also with increased brittle hair, as well as dry skin. In addition, vitamin A is included in many anti-aging creams.
What is vitamin A?
Vitamin A is a fat-soluble vitamin that is an important component of the human immune system and the maintenance of a healthy metabolism. It regulates the processes of healing, renewal, and growth of body tissues, being part of the eyes, skin, hair, teeth, muscles, and various internal organs.
Due to the synergy with collagen, retinol is beneficial for the skin and accelerates the healing of wounds – including psoriasis and eczema. In addition, vitamin A is needed to neutralize the negative effects of free radicals – for example, it slows down the growth of cancer cells.
Vitamin A is found in most animal foods – in fish oil, eggs, butter, milk, and beef liver. Also in the form of beta-carotene, it is found in many plant foods – for example, in red and yellow vegetables (carrots, pumpkin, rose hips, and so on), as well as in spinach.
Daily intake of vitamin A:
- For men – 1mg/day (3000 IU)
- For women – 0.8mg/day (2300 IU)
- For teenagers – 0.6mg/day (2000 IU)
- For children – 0.3 – 0.4mg
Benefits of Vitamin A
Vitamin A is needed by the skin and mucous membranes both to maintain health and to regenerate after damage. One of the key functions of retinol is to improve the synthesis of collagen, a building material for the connective tissues of the body.
Retinoids (synthetic analogs of vitamin A) are found in many cosmetic products for treating skin and prolonging its youth – ranging from anti-wrinkle cream and sunburn lotion to acne medications and stretch mark creams.
Scientific studies show that retinol is one of the few compounds that actually improves skin health. In addition, vitamin A is useful for restoring immunity after an illness, as well as for athletes training for muscle growth.
However, an excess of vegetable beta-carotene in the diet is manifested by yellow staining of the skin – for example, with regular and excessive use, carrots containing vitamin A can give a yellowish tint to the skin and whites of the eyes. In addition, taking vitamin A capsules is incompatible with a course of antibiotic treatment or taking various anticoagulants.
Foods containing Vitamin A
In nature, there are several variations of vitamin A, which differ in chemical structure and have different percentages of assimilation by the human body. The original vitamin A (retinoid) is found mainly in animal products – in caviar, liver of fish and animals, chicken eggs, all kinds of cheese, butter, full-fat cottage cheese, and whole milk.
Vegetables and fruits contain carotenoids in the form of beta-carotene, which is converted into vitamin A during digestion. Despite the level of absorption of such beta-carotene is lower than the absorption of animal vitamin A (1 μg of beta-carotene from carrots or pumpkins equates to 1/12 or even 1/24 μg of retinol from the liver of marine fish), daily norms take into account this fact.
Most vitamin A is found in animal products – in the first place, animal liver (especially cod liver oil). In smaller quantities – in eggs, milk, cheese. Also in the form of carotene, vitamin A is also found in plant foods. The daily requirement of vitamin A implies coverage of 40% of the norm in the form of animal products, and 60% – in the form of vegetable products.
| Product | Vitamin A (per 100g) | Daily Value |
| Cod liver oil | 30000 mcg | 3333% |
| Turkey liver | 8000 mcg | 895% |
| Beef, pork, fish liver | 6500 mcg | 720% |
| Chicken liver | 3300 mcg | 370% |
| Sweet red pepper | 2100 mcg | 230% |
| Yam (sweet potato) | 1000 mcg | 110% |
| Carrot | 830 mcg | 93% |
| Broccoli | 800 mcg | 90% |
| Butter | 680 mcg | 75% |
| Green salad | 550 mcg | 63% |
| Spinach | 470 mcg | 52% |
| Pumpkin | 430 mcg | 43% |
| Cheddar cheese | 265 mcg | 30% |
| Melon | 170 mcg | 20% |
| Eggs | 140 mcg | 16% |
| Apricot | 100 mcg | 16% |
| Tomatoes | 40 mcg | 5% |
| Polka dots | 38 mcg | 4% |
| Milk | 30 mcg | 3% |
| Green pepper | 18 mcg | 2% |
Hypervitaminosis
Since vitamin A is fat soluble, it not only requires fatty acids for successful absorption but it can also be stored in the body’s fatty tissues. In this case, it toxically affects the liver, causing a number of health complications. Symptoms of acute carotene hypervitaminosis are vomiting, dizziness, diarrhea, and yellowness on the skin.
However, an overdose of vitamin A can be caused solely by the joint intake of several sources of carotenes at once – for example, in the form of food rich in vitamin A, as part of a multivitamin complex, and in the form of an anti-aging cream. Eating foods that contain vitamin A, even in large quantities, cannot lead to hypervitaminosis.
Vitamin A and smoking
When studying the effect of high doses (20-30 mg/day) of carotenoids with long-term use, data were obtained on an increase in mortality from lung cancer among long-term smokers who took this vitamin. This result confirms the need for caution in the use of dietary supplements, including vitamins, in individuals at risk of developing cancer.
Vitamin A is the most important fat-soluble vitamin that affects both the production of sex and thyroid hormones and the processes of renewal of various body tissues. Lack of vitamin A provokes a deterioration in the condition of the skin, hair, and muscles, provoking early aging. Taking in the form of supplements can lead to hypervitaminosis, which is especially dangerous for smokers.