If you picked up any grocery item and read through its ingredient list, you’ll almost definitely see vitamin A. It doesn’t matter what grocery item it is; vitamin A somehow seems to find its way into them, meaning it must be pretty important, right? Well yes. This vitamin is one of the essential ingredients for the body. While it’s popularly portrayed as good for the eyes, it does much more than that.
I’m sure you’re wondering, what more could this little guy do for the body other than help you see in the dark? Well, a lot! If you keep reading, you’ll discover the wonder that vitamin A is.
What is Vitamin A?
Vitamin A is the name given to naturally occurring chemicals needed for proper body functioning. Unlike vitamins B and C, vitamin A is not easily passed out from the body through urine. This makes it a member of the fat-soluble vitamins, including vitamins D, E, and K.
Vitamin A exists in different forms. There are two common forms of vitamin A obtained from dietary sources;
- Preformed vitamin A (retinoids): are commonly found in meat, fish, poultry and dairy products. These forms of vitamin A are bioavailable, meaning the body readily uses them after intake.
- Provitamin A (carotenoids): are commonly found in plant-based foods like vegetables, fruits and oils. Cartenoids are mainly responsible for the color of these fruits. Unlike retinoids, carotenoids must first be broken down by β-carotene before the body can use them.
Both performed and provitamin A are converted into retinol in the body. After being used, excess retinol is stored in the liver as retinyl ester. Then, Retinyl ester is broken down to trans-retinol to be used by the body again.
Why We Need Vitamin A
Vitamin A is one of the most vital molecules for the body. It is essential for growth and development, cell recognition, immunity, reproduction, and good vision.
Zero or inadequate intake of vitamin A will result in vitamin A deficiency, also known as xerophthalmia. Vitamin A deficiency is marked by problems with vision, which occur in different stages.
- Mild deficiency is characterized by night blindness and Bitot spots
- Severe deficiency is characterized by corneal dryness, resulting in retinal and corneal damage from cell death. The result is blindness.
Vitamin A deficiency also limits the body’s ability to fight infections, especially in children. It also increases their risk of contracting measles, diarrhea, and respiratory infections and slows their growth rate and bone development.
Vitamin A deficiency is rare and mostly occurs in pregnant women and children from developing countries. However, vitamin A deficiency is the leading cause of child blindness worldwide. In pregnant women, vitamin A deficiency causes low blood count and slows the growth and development of the fetus.
Vitamin A is also needed to cure acne, protect against aging skin, protect against devastating effects of HIV/AIDS, and boost the immune system.
Sources of Vitamin A
The recommended daily allowance (RDA) for vitamin A for men and women is 900 and 700 micrograms of retinol activity equivalents (RAE) per day. On the other hand, values of 3000micrograms and above per day may cause problems.
Many foods easily reach the RDA for vitamin A. Animal-based foods provide preformed vitamin A, which is quickly absorbed and used by the body. In contrast, plant-based foods are rich in provitamin A carotenoids. The body converts these forms into active vitamin A before use.
The body’s ability to convert provitamin A carotenoids depends on genetics, diet, presence of diseases, and use of medications. Thus, if you follow a vegan diet, you have to be conscious about your vitamin A intake by eating fruits/vegies with higher vitamin A content.
The table below lists foods rich in vitamin A from plant and animal-based sources and their specific vitamin A content.
Vitamin A is also gotten in rich quantities from various supplement formulations. Some of these supplements contain the preformed vitamin A, while others contain provitamin A carotenoids, and others contain a mix of both.
Vitamin A in supplements is usually vitamin A palmitate, also known as retinyl palmitate. Retinyl palmitate is a preformed vitamin A, which has high bioavailability.
Supplements provide an easy means to maintain adequate vitamin A intake since food sources may be difficult to get or may not contain adequate vitamin A. Some of the most effective vitamin A supplements include
|Supplement||Vitamin A Content (mcg RAE)||%DV|
|Bulk Supplements Vitamin A Palmitate||2512||279|
|Bulk Supplements Vitamin A Softgels||3000||333|
|Amazon Choice Bronson 10000 IU Vitamin A ||3000||333|
Vitamin A content in supplements may be expressed in mcg RAE or international units (IU). To avoid confusion, understand that 1 IU = 0.3 mcg RAE. Thus, a supplement with 10,000 IU vitamin A will contain (0.3 x 10000) = 3000 mcg RAE vitamin A.
Benefits of Vitamin A
An adequate intake of vitamin A is necessary for proper body functioning. Whether your source is from diet or supplements, you should expect the following benefits when optimizing your vitamin A intake.
Protection against night blindness and age-related vision loss: Vitamin A is an essential component of rhodopsin, a pigment in the retina which converts light into electrical signals that the brain interprets to make you see. Adequate vitamin A intake allows the rhodopsin to function optimally, interpreting information from very small light exposure. Thus, people with vitamin A deficiency suffer night blindness where they can see well in the day but will not see well at night.
Research has also shown Vitamin A to help slow down vision loss in older people. This is because vitamin A has potent antioxidant activity, thus protecting against oxidative stress that causes retinal damage and eventual vision loss. In addition, a study found that giving elderly people vitamin A supplements reduced the risk of macular degeneration by 25%.
Reduced risk of certain cancers: Vitamin A is a potent antioxidant, thus protecting against oxidative stress, a major cause of many cancers. Vitamin A is also required for healthy cell division and growth. Cancer cells do not divide similarly to healthy cells and thus may be inhibited by vitamin A. While these two mechanisms may underlie vitamin A’s anticancer benefit, the exact mechanism is unknown.
However, what is known is that Adequate intake of beta carotene and plant-based vitamin A is associated with reduced risks of cancers like cervical, thyroid, lung, and bladder cancer. Intake of vitamin A supplements is also linked with reduced cancer risk. However, animal-based vitamin A sources have not been linked to similar benefits.
Improved Immunity and Protection from Diseases: Vitamin A is essential in maintaining the body’s defense systems. It is an essential component of entry barriers like the eyes, lungs, gut and genitals that prevent entry and growth of bacteria, fungi and other infectious agents.
Vitamin A is also essential in white blood cell formation and functioning. The white blood cells are the major defense systems in the body; thus, vitamin A supplementation to boost their production enables the body to fight against various diseases like measles and respiratory illnesses effectively.
Reduced risk of acne and clearer skin: Acne is a big problem for many teenagers and early adults. It is a chronic inflammatory skin disorder that affects people’s self-confidence. Studies suggest that vitamin A deficiency causes acne, although the exact way it does it is unknown.
One explanation for vitamin A benefits for acne is that vitamin A deficiency increases the amount of keratin in your body. Increased keratin means your body finds it hard to get rid of dead cells. The accumulated dead cells then cause your pores to clog, causing acne. Vitamin-A cream isotretinoin is used in the treatment of acne with great effect.
Healthy Growth and Reproduction: Vitamin A is an essential component of both the male and female reproductive systems. It also ensures the normal growth of the fetus during pregnancy.
Studies have shown that vitamin A deficiency can block the development of sperm cells, leading to low sperm motility and eventual infertility. In addition, studies in women show that vitamin A deficiency causes poor egg quality and makes it difficult for implantation to occur. Vitamin A is essential for forming many organs in developing fetuses, including the skeleton, nervous system, kidneys and lungs.
Healthy bones and muscle: Studies have shown that vitamin A positively affects bone health. This vitamin is an essential component of bone-building cells known as osteoblasts. Increased osteoblasts mean that more bone cells can form, resulting in denser, healthier bones. However, vitamin A also influences the production of bone-breaking cells and may cause an increased risk of fractures.
Vitamin A is pivotal in protein synthesis, essential for muscle development and recovery. Therefore, vitamin A intake leads to faster muscle growth and faster recovery from muscle injuries.
Excess intake and toxicity
As much as vitamin A deficiency is bad, you should also avoid excessive intake. You mustn’t exceed the upper limit of intake, which is 3000 micrograms per day. Taking values above that may lead to acute toxicity.
Since vitamin A is stored in the liver, excessive intake repeatedly will lead to accumulated/chronic toxicity.
Vitamin A toxicity rarely results from dietary sources but commonly from supplements and vitamin A-based medications like isotretinoin. Thus, it would be best not to use any supplement more than prescribed.
The most common effects of vitamin A toxicity include;
- Delayed growth
- Dry skin
- Hair loss
- Itchy skin
- Joint and bone pain
- Liver damage
- Nausea and vomiting
- Sunlight sensitivity
- Vision disturbances
Effects on Bodybuilding
Vitamin A is also beneficial to athletes, fitness enthusiasts, and bodybuilders. This is because vitamin A plays a crucial role in protein synthesis. Protein synthesis is an essential process in muscle development and bulking. Vitamin A is also crucial in testosterone production. Testosterone is the most potent bodybuilding hormone, providing another benefit of vitamin A for bodybuilding.
Another way vitamin A aids bodybuilding is to provide structural strength to muscles. This vitamin aids in the rapid growth of muscles and promotes optimal bone health.
Vitamin A is a must-have in your diet. You should look to incorporate this through plant and animal-based foods high in vitamin A or getting vitamin A supplements. However, ensure that you do not take more vitamin A than you require. Toxicity is just as bad as a deficiency. Speak with a doctor if you’re on other medications and adhere strictly to your dosage. If you’re taking vitamin A for bodybuilding, try to combine it with other necessary bodybuilding supplements for better results.