Vitamin A: The Missing Piece in Your Health Puzzle
The discovery of Vitamin A was an important milestone in the field of nutrition and greatly improved our understanding of the importance of a balanced diet for maintaining good health.
Back in 1912, Frederick Hopkins discovered that there were other substances in milk that rats needed to grow, and it wasn’t just the usual suspects like carbs, proteins, and fats.
By 1913, one of these substances was independently discovered by two different groups of scientists. Elmer McCollum and Marguerite Davis at the University of Wisconsin–Madison, and Lafayette Mendel and Thomas Burr Osborne at Yale University. McCollum and Davis received credit because they submitted their paper three weeks before Mendel and Osborne. The substances were called “fat-soluble” in 1918, and later “vitamin A” in 1920.
What is vitamin A?
Vitamin A is a fat-soluble vitamin, meaning it is dissolved in fats and oils and can be stored in the body’s fatty tissue. It is not a single compound, but rather a group of chemically related compounds.
Two forms of vitamin A are found in food: Preformed vitamin A and provitamin A carotenoids. To use both of these forms, our body needs to convert them to retinal and retinoic acid, the active forms of the vitamin.
Additionally, there are synthetic forms of Vitamin A, such as retinyl palmitate and retinyl acetate, which are used in dietary supplements and fortified foods. These forms of Vitamin A are chemically identical to the natural forms but are created in a lab.
Vitamin A health benefits
Vitamin A is an essential nutrient that plays a crucial role in maintaining overall health and well-being. Here is a list of health benefits:
- Protects eyes from night blindness and age-related decline: It is essential for preserving eyesight, it helps the retina, the part of the eye that detects light, to function properly.
- Antioxidant properties: It may protect cells against the effects of free radicals, molecules produced when the body breaks down food or is exposed to tobacco smoke and radiation.
- Eye health: Adequate dietary intake of vitamin A helps protect against certain eye diseases such as age-related macular degeneration.
- Organ health: Vitamin A benefits nearly all the organs in your body. It supports the growth of the cells and tissues needed for organs like the heart, lungs, and kidneys to function. Early vitamin A deficiency during preconception or pregnancy could lead to altered gene expression, impacting the baby’s heart.
- Anti-aging vitamin: Vitamin A benefits are wide-reaching and have an influential role in brain function, skin, heart, kidneys, lungs, vision, and immune system health.
Foods rich in vitamin A
As we pointed out above, we can find two forms of vitamin A in food: Preformed vitamin A and provitamin A carotenoids.
Preformed Vitamin A (aka retinol) is only found in animal-sourced foods. Animal sources include:
- Liver and organ meats
- Egg yolks
- Dairy products such as milk and cheese
- Fish such as salmon, tuna, and cod liver oil
Your body also can produce vitamin A from carotenoids found in plants. Plant sources include:
- Orange and yellow fruits and vegetables such as carrots, sweet potatoes, pumpkins, and cantaloupe
- Dark green leafy vegetables such as spinach, kale, and collard greens
- Peppers, apricots, and papaya
- Some fortified foods such as breakfast cereals and milk
It’s important to note that beta-carotene, which is found in plant-based foods, needs to be converted by the body into retinol, the active form of Vitamin A, so not all of the beta-carotene consumed will be converted into Vitamin A.
It’s recommended to eat a balanced diet with a variety of fruits, vegetables, and animal products to meet the daily recommended intake of Vitamin A. Also, it’s important to take into account that cooking, processing, or preservation methods can affect the nutrient content of the food.
Vitamin A deficiency
A deficiency of Vitamin A can cause a number of health problems. The symptoms and effects of Vitamin A deficiency can vary depending on the severity and duration of the deficiency.
Some common symptoms of Vitamin A deficiency include:
- Night blindness, or difficulty seeing in low light or darkness
- Dry, itchy eyes
- Dry, scaly, or rough skin
- Slow wound healing
- Dry, cracked lips
- Increased susceptibility to infection
Severe Vitamin A deficiency can cause more serious health problems such as:
- Xerophthalmia, a condition that can lead to blindness
- Increased risk of death from infections
- Delayed growth and development in children
- Increased risk of maternal mortality during pregnancy and childbirth
- Poor bone health and risk of fractures.
Vitamin A deficiency is most common in developing countries, where a lack of access to a balanced diet can make it difficult for people to get enough of this vitamin. However, it can also occur in developed countries, particularly in people with malabsorption disorders, people with type 1 diabetes, those who have a poor diet, or those who are fasting.
If you suspect that you may have a Vitamin A deficiency, it is important to consult a doctor or a registered dietitian for an evaluation, proper treatment, and help to build a healthy dietary pattern. Treatment usually involves a higher intake of Vitamin A either through diet, other dietary supplements, or fortified food.
Vitamin A excess
Consuming too much Vitamin A can lead to toxicity, which can cause a number of harmful effects. The symptoms of Vitamin A toxicity can vary depending on the amount and duration of the excess intake.
Some common symptoms include:
- Nausea and vomiting
- Dry, itchy skin
- Loss of appetite
- Joint and muscle pain
In more severe cases, can lead to more serious health problems such as:
- Birth defects in pregnant women
- Liver damage
- Bone pain and fractures
- Drowsiness and confusion
The upper limit for Vitamin A intake is 3000 mcg/day for adults. It’s important to be aware that consuming high doses of Vitamin A in the form of supplements can be harmful, as it can lead to toxicity and further health issues.
Here are a few fun facts about Vitamin A:
- It is a fat-soluble Vitamin, that requires fat for effective absorption.
- It helps cut down excess sebum production, which reduces the risk of acne and acne-related breakouts.
- Popeye the Sailorman, the famous cartoon character, is known for his love of spinach, which is high in Vitamin A.
- Beta-carotene, a form of Vitamin A found in plants, is responsible for the orange color in fruits and vegetables like sweet potatoes, carrots, and pumpkins.
- Consuming about 2 egg yolks per day provides all the required Vitamin A.
- A polar bear’s liver is so rich in Vitamin A that eating an entire liver can be fatal to humans.
Why is Vitamin A important for sports performance?
Vitamin A is essential for sports performance in several ways:
- Vision: Vitamin A plays a crucial role in maintaining good vision, it’s essential for the proper functioning the retina, the part of the eye responsible for sensing light and sending visual information to the brain. This is especially important for sports that require good visual acuities, such as baseball, tennis, and golf.
- Immunity: Vitamin A helps to boost the immune system, by promoting the production of white blood cells that fight off infection and disease.
- Muscle growth: Vitamin A plays a role in the growth and repair of body tissues, including muscle. This is important for athletes, as muscle growth and repair are essential for maintaining strength and endurance.
- Healthy skin: Vitamin A also helps to keep skin healthy and moisturized, this is important for athletes, as skin may be exposed to the sun, wind, and other environmental factors during training or competitions.
It’s important for athletes to consume a balanced diet that includes foods rich in Vitamin A to ensure that they are getting enough of this essential nutrient.
To sum up, we learned that vitamin A is a really important nutrient that our body needs for things like vision, immune function, and cell growth. It’s found in a bunch of different foods like sweet potatoes, carrots, and leafy greens. And it’s also available as a supplement if you’re not getting enough through your diet. It’s important to note that getting too much vitamin A can also be harmful, so it’s important to talk to a healthcare professional before starting any supplement regimen. A healthy, balanced diet is the best way to provide your body with a safe amount of this essential nutrient.