Vitamin A

Vitamin A is a fat-soluble nutrient essential for various bodily functions, including vision, immune system support, and cell growth. It exists in two forms: preformed vitamin A (retinol) found in animal products, and provitamin A carotenoids found in plant-based foods. The human body converts these carotenoids into active vitamin A. Research has shown that vitamin A plays a crucial role in maintaining healthy eyesight, particularly night vision, and supports the proper functioning of organs such as the heart, lungs, and kidneys.

Key Facts

• Vitamin A is crucial for maintaining healthy vision, especially in low-light conditions.
• It supports immune function and helps the body fight off infections.
• Vitamin A is essential for proper foetal development during pregnancy.
• The body stores excess vitamin A in the liver for future use.
• Provitamin A carotenoids, such as beta-carotene, also act as antioxidants in the body.
• Excessive intake of preformed vitamin A can be toxic, but overconsumption of carotenoids is generally not harmful.

What does the research say about vitamin A and its function in the body?

Research indicates that vitamin A is crucial for maintaining healthy vision, supporting immune function, and promoting cell growth and differentiation. Studies have shown its importance in reducing childhood mortality and morbidity, particularly in developing countries where vitamin A deficiency is more prevalent.

What are the primary food sources of vitamin A?

The primary sources of preformed vitamin A include liver, fish oils, milk, and eggs. For provitamin A carotenoids, good sources include orange and yellow fruits and vegetables like carrots, sweet potatoes, and mangoes, as well as leafy green vegetables such as spinach and kale.

How can I supplement vitamin A?

Vitamin A supplements are available in various forms, including tablets, capsules, and liquid drops. It's important to consult with a healthcare professional before starting supplementation, as excessive intake can be harmful. Many multivitamins also contain vitamin A in appropriate doses.

What are the main symptoms of vitamin A deficiency?

The main symptoms of vitamin A deficiency include night blindness, dry eyes, impaired immune function, and skin problems. In severe cases, it can lead to complete blindness, increased susceptibility to infections, and growth retardation in children.

Are there any known side effects of supplementing vitamin A?

Excessive intake of preformed vitamin A can lead to toxicity, causing symptoms such as nausea, headaches, blurred vision, and in severe cases, liver damage. However, high intake of provitamin A carotenoids is generally not associated with adverse effects, aside from temporary skin discolouration.

How long does it take to see the benefits of vitamin A supplementation?

The time to see benefits from vitamin A supplementation can vary depending on the individual's initial vitamin A status and the specific condition being addressed. For vision improvements, some people may notice changes within a few weeks, while other benefits may take several months to become apparent.

What should consumers look for on the supplement label when supplementing vitamin A?

When choosing a vitamin A supplement, look for the type of vitamin A (retinol or beta-carotene), the dosage in International Units (IU) or micrograms (mcg), and the percentage of the Daily Value (%DV). Ensure the supplement doesn't exceed 100% of the daily recommended intake unless advised by a healthcare professional.

Can vitamin A help with acne?

Vitamin A derivatives, particularly retinoids, are often used in topical treatments for acne. These compounds help regulate skin cell turnover and reduce inflammation. While oral vitamin A supplements may have some benefit, topical applications are generally more effective and safer for acne treatment.

Is it possible to get too much vitamin A from food?

It's unlikely to get too much vitamin A from food sources alone, except for consuming large amounts of liver regularly. However, excessive intake of preformed vitamin A from supplements can lead to toxicity. Provitamin A carotenoids from fruits and vegetables don't pose a risk of toxicity.

How does vitamin A support immune function?

Vitamin A supports the immune system by maintaining the integrity of mucosal barriers in the body, which act as the first line of defence against pathogens. It also plays a role in the production and function of white blood cells, which are crucial for fighting infections and diseases.

Written by Christian Jakobsson