Vitamin A Is Key To Health And Beauty

Clara Joaquim, a member of the Spanish Society of Endocrinology and Nutrition (SEEN), explains that there are two main forms of vitamin A.

On the one hand, there are retinoids (retinol, retinal, retinoic acid) that come from animal sources and are the most active forms. On the other hand, there are carotenoids (provitamin A), of plant origin. “β-carotene is the only one that can be metabolized into retinal in mammals, a necessary step for its absorption,” he points out.

Vitamin A is very important for vision. In this regard, Dr. Joaquim states that vitamin A “participates in the vision process, both in phototransduction and in color vision, since retinal is incorporated into the photoreceptor cells.”

Phototransduction is the process by which the information captured by the photoreceptor cells of the eye is transformed into an electrical signal and sent to the brain, which recognizes and interprets it.

Additionally, vitamin A plays a prominent role in the cellular health of the conjunctiva and retina and is necessary for conjunctival and corneal development in the fetus.

Vitamins in animal and plant foods

The endocrinologist explains that the foods of animal origin that contain the most vitamin A are: meat (especially organ meats such as kidney or liver), egg yolk, and dairy products such as butter.

As for plant-based foods rich in vitamin A, there are green leafy vegetables, sweet potatoes, carrots, and greens, as well as brightly colored fruits such as peppers.

Dr. Joaquim says that “to obtain an adequate intake of vitamin A, the diet should be varied and include eggs, dairy products, green leafy vegetables such as spinach; vegetables such as carrots or tomatoes; and fruits such as apricots or mangoes.”

The endocrinologist explains that in underdeveloped countries, vitamin A deficiency is common due to poor nutrition.

However, in those with higher incomes, “only people with diseases that cause fat malabsorption, such as cystic fibrosis, celiac disease, pancreatitis, Crohn’s disease or those who have a gastric bypass due to morbid obesity, will need to take supplements.”

However, taking vitamin A supplements should always be done under the prescription of specialized health personnel, since excess vitamin A can have negative consequences for the body.

In this regard, Dr. Joaquim explains that “the intake of vitamin A from plants can rarely cause toxicity, since the transition from β-carotene to retinal is dependent on the levels of vitamin A in the body.”

“However, the intake of retinoids from animal products and nutritional supplements can cause toxicity,” she clarifies.

The endocrinologist stresses that toxicity often occurs as a result of taking large amounts of synthetic retinol supplements, approximately 50,000 IU (international units) per day.

“Ingestion of a single, very high dose (more than 600,000 IU) can cause nausea, vomiting, blurred vision, and dizziness. Meanwhile, prolonged intake of more than 33,000 IU per day can cause gait instability, alopecia, visual disturbances, liver toxicity, and an increased risk of bone fractures,” he said.

Skincare

On the other hand, vitamin A is a highly valued substance for skin care. “Dermatologists talk about topical retinoids to refer to all those molecules derived from vitamin A that have anti-aging properties,” says Cristina García Millán, a member of the Spanish Academy of Dermatology and Venereology (AEDV).

“Topical retinoids have demonstrated their efficacy and safety in the treatment of aging and photoaging. There is also evidence supporting the use of topical retinoids, either as monotherapy or in combination with other topical agents, in the treatment of pigmentary disorders such as melasma, solar lentigines, and post-inflammatory hyperpigmentation,” she says.

The dermatologist says that topical retinoids are suitable for all skin types and many skin conditions, except for very sensitive and intolerant skin.

However, he stresses that the concentration must be adapted to the age, the condition of the skin, and the objectives that are to be achieved.

Vitamin A is present in a multitude of products. “We can find drugs with tretinoin for the treatment of acne and many cosmetics (serums, creams, etc.) with different concentrations of retinol,” she points out.

For those who want to start using cosmetics with vitamin A, to avoid irritation, Dr. García recommends introducing them gradually and at low concentrations and then gradually increasing the frequency and concentration. In addition, the specialist indicates that it is preferable to apply them at night.

However, pregnant women should take certain precautions. “It has not been proven that retinol has a teratogenic power (capable of causing malformations in the fetus) secondary to its application during pregnancy due to its low percutaneous absorption. However, it is advisable to suspend or avoid treatment with topical tretinoin during pregnancy since there are no epidemiological studies on the subject,” the dermatologist specifies.