September 12 2021
Vitamin A is a group of fat-soluble chemicals called retinol, retinal, and retinyl esters. It is involved in the functioning of the immune system, cellular system, and reproductive system. It is also essential for vision and supports cell growth as well as differentiation, which makes it an important aspect of the formation and maintenance of the heart, kidney, lungs, and other organs of the body. Two forms of vitamin A are available in the dietary intake of humans- provitamin A carotenoids and preformed vitamin A. Preformed vitamin A is found in animal-based foods like dairy products, fish, and meat.
Sources of vitamin A
- Dairy products: dairy products are an excellent source of vitamin A, naturally. However, many types of milk are fortified with this essential vitamin to make it more nutritious. One serving of milk can have between 100 to 300 mcg of vitamin A, depending on the source of it.
- Cod liver oil: livers of fish are also very good sources of preformed vitamin A; just one tablespoon of this oil can contain 4080 mcg of vitamin A. fish oils contain high amounts of omega-3 fatty acids which can be beneficial in preventing inflammation and protect the body from many diseases. These oils also contain a good amount of vitamin D, i.e. 170 percent of DV in one tablespoon. You can also consider taking supplements of fish oil, which is rich in omega-3 fatty acids, like alvizia’s fish oil supplement (alenfish).
- Sweet potato: one baked sweet potato contains 1403 mcg of vitamin A. the content of vitamin A present in sweet potatoes is in the form of beta carotene, which is a compound that protects from age-related macular degeneration. Many research studies suggest that beta carotene also protects the body from carcinogenic substances, however, the results are mixed and more research is needed for this benefit of sweet potatoes.
- Carrots: carrots are considered as one of the best sources of vitamin A- half one cup of uncooked carrots contains 918 mcg of this vitamin. They contain beta carotene and are a healthy and light snack to have. Other than vitamin A, they also contain dietary fiber, which is beneficial in preventing constipation and promoting gut health.
- Spinach: one cup of boiled spinach can provide you with 1146 mcg of vitamin A. Like all the green and leafy vegetables, spinach is packed with the goodness of many nutrients. It also contains magnesium, iron, folic acid, fiber, potassium, proteins, healthy fats, and vitamin E, other than vitamin A. Research studies suggest that spinach may also lower blood pressure and enhance heart health.
- Mangoes: Mangoes are a rich source of antioxidants and fiber- these two components enhance gut health and also control the levels of blood sugar. One raw mango contains around 112 mcg of vitamin A. It is eaten raw, and as a topical dressing on fruit salads.
- Apricots: ten pieces of dried apricots contain around 63 mcg of vitamin A. They also have high levels of antioxidants and dietary fiber. They can be consumed as a snack or a sweet treat. However, dried apricots also have high levels of calories and sugar content, which is why it is advised to consume them in moderation.
- Pumpkin pie: one piece of pumpkin pie contains 488 mcg of vitamin A, as; it is rich in beta carotene. Other than this benefit, it also provides antioxidants like vitamin C and lutein, a higher intake of which can be beneficial for the eyes (vision and prevention of eye diseases).
- Black-eyed peas: beans are considered very well when it comes to consuming plant-based proteins. Other than this, they are packed with the goodness of vitamin A (66 mcg per serving), iron, and dietary fiber. As per the research, they promote heart health, lower high blood pressure in hypertension patients, and also reduce the risk of type-II diabetes.
Role of vitamin A in the human body
- Immune functions: vitamin A is associated with better functioning of the immune system. It affects the immune health by stimulating some responses which can protect the body from infections and diseases. It is also involved in the development of certain types of cells, like B-cells and T-cells which are known for their vital roles in immune functions. Deficiency of vitamin A leads to enhanced levels of pro-inflammatory molecules that deteriorate the functioning of the immune system.
- Fertility: vitamin A plays a major role in the functioning and enhancement of reproductive health. It is involved in the development of both male and female gametes. It also determines the health of the placenta, fetal tissues, and the growth and development of the fetus. Henceforth, vitamin A is considered an integral component required by the human body for maternal and fetal health.
- Eye health: vitamin A enhances eye health and prevents certain conditions like age-related macular degeneration. It is essential for vision. Many research studies have suggested that high levels of beta carotene in the blood can reduce the risk of age-related macular degeneration by up to 25 percent.
- Antioxidant properties: vitamin A possesses antioxidant properties that help in fighting off free radicals, which are the reactive molecules that may cause harm to the human body by developing a condition called oxidative stress. Oxidative stress has been linked to many chronic diseases like diabetes, heart disorders, and cognitive decline. Consumption of carotenoids is associated with a lower risk of chronic disorders.
Deficiency of vitamin A
Deficiency of vitamin A can be caused due to poor or inadequate intake of the nutrient, poor absorption of fats, and liver disorders. It is associated with impaired immune function and may cause rashes and some ocular effects. Vitamin A deficiency may also lead to a condition known as hematopoiesis.
The diagnosis of this nutrient deficiency is based on ocular findings which have lower levels of vitamin A.