What is vitamin A good for?
Primary functions of vitamin A
Vitamin A is fundamental for the correct function of a variety of processes in the human body, including eye health, bone health, reproductive health and immune system function, as well as aiding in the healthy development of the fetus during pregnancy.Consequently, a deficiency in vitamin A can result in a large amount of health problems, such as poor eyesight, poor bone health, decreased fertility, or a weakened immune system, which can in turn lead to further disease and illness.
People who follow a diet that is poor in nutrition are susceptible to vitamin A deficiency, and people that suffer from certain conditions such as pancreatic disease or a disease of the eyes could also require a higher amount of vitamin A than normal.
Role in eye health
As you have probably concluded by this point, vitamin A is essential for our eyesight, and this is because it is precisely vitamin A that helps to convert the light that hits our retinas into the electrical signal that is sent to the brain for visual interpretation.In fact, one of the first symptoms of vitamin A deficiency is the inability to see properly in dark environments, a condition known as nyctalopia, or night blindness.
Role in bone health
Vitamin A is also important for bone health, as it is one of the nutrients involved in bone strength and density, and a deficiency in vitamin A is associated with poor bone health and an increase in the risk of suffering a fracture.Role in the immune system
Regarding its importance for our immune system, vitamin A is involved in the production and function of leukocytes, our white blood cells, which are tasked with protecting our body from harmful foreign bacteria and pathogens. It also contributes toward the protective mucous barriers that keep our eyes, lungs and gut safe from infection.In developing countries, where diseases such as malaria or measles are common, vitamin A supplementation in children features heavily in the child mortality research, which is a big part of why vitamin A is taken so seriously in those settings.
Role in reproductive health
Vitamin A is essential both in the healthy development of sperm cells as well as egg quality and the egg's ability to implant itself in the womb. A deficiency in vitamin A can affect fertility in both cases, and vitamin A is also vital for the healthy growth and development of the child throughout pregnancy.Excessive intake of vitamin A
However, all this said, don't go reaching for that bottle of vitamin A capsules just yet. It is important to understand that an excess of vitamin A can be dangerous.Being a fat-soluble vitamin, the body will attempt to store as much of it as possible, which means that excess consumption of vitamin A can lead to toxic levels of the vitamin accumulating in the body, a condition known as hypervitaminosis A.
Symptoms of this type of hypervitaminosis can result in nausea, dizziness, or even more serious conditions resulting in damage to vital organs. It is quite hard to achieve an excess of vitamin A through diet alone, unless you are eating liver very frequently, but it can be relatively easy if you are unnecessarily taking vitamin A supplements, so make sure you check with your doctor to see if you really need it first!
When should I take vitamin A?
Vitamin A is fat-soluble vitamin, which means that for optimal absorption, it should be taken with a meal that contains dietary fat, such as fish, fatty meat, nuts, seeds, avocados, and similar foods, although there does not seem to be a particular time of day that is best suited for taking vitamin A.
What does vitamin A combine well with?
Vitamin A with ox bile, taken together, for fat-soluble absorption
If you are taking ox bile supplements, they belong in the same sitting as vitamin A when the meal actually contains fat, as bile salts form the mixed micelles that carry vitamin A to the gut wall, enhancing absorption.What else pairs well with vitamin A?
Also taken with vitamin E, for increased absorption of vitamin A
Intestinal absorption of vitamin A has been shown to improve significantly when taken in the presence of vitamin E, and you will often see vitamin A combined with vitamin E in some supplement formulations (together with vitamin C as well), so that is worth considering if you want to get the most from your vitamin A.What should I avoid taking vitamin A with?
Avoid taking vitamin A at the same time as multivitamin or prenatal multivitamin
A multivitamin, and especially a prenatal multivitamin, may already contain vitamin A as retinol, so a separate vitamin A capsule beside will most likely be excessive.Avoid taking vitamin A at the same time as plant sterols
Vitamin A is stored in the liver, and plant sterols also put the liver to work, so when both are taken in one sitting, they can increase the liver's workload excessively.Avoid taking vitamin A at the same time as cod liver oil
Cod liver oil already brings vitamin A in the form of retinol ready to use, alongside its vitamin D and omega-3 content, so a separate vitamin A capsule on top of this becomes excessive.What are natural sources of vitamin A?
If you are interested in obtaining your daily vitamin A through your diet, you can often find it in:
Who should avoid taking vitamin A?
Before taking vitamin A supplements, check with your trusted healthcare professional if any of the following apply to you:
- Liver problems
Vitamin A is stored in your liver, so a diagnosis of liver disease is the situation where a preformed retinol supplement can build up and add to an organ that is already struggling.
Remember to always discuss any vitamins or supplements with your trusted healthcare professional if you are suffering from any health conditions.
Possible side effects of vitamin A
Possible side effects from taking vitamin A supplements may include (but are not limited to) the following:
- Headache
- Liver damage
- Birth defects at excess retinol
If you are experiencing negative side effects from taking vitamin A supplements, stop taking them immediately and reach out to your trusted healthcare professional.
Drug interactions with vitamin A
The medicines listed below are the ones most often named in interaction reports for vitamin A, but it is by no means a comprehensive list:
- Blood thinners
- Orlistat
Blood-thinning medication
Vitamin A can have negative interactions with blood thinners, so make sure to take any blood-thinning medication at least three hours apart from any supplements containing vitamin A.If you are taking any prescription drugs or medication, check with your trusted healthcare professional before taking vitamin A supplements.
Can I take vitamin A while pregnant or breastfeeding?
Your prenatal multivitamin usually brings a small amount of vitamin A, but it's the total across the prenatal and any separate capsule that matters, so make sure you check every label to avoid inadvertently taking too much vitamin A.
Breastfeeding raises the requirement to about 1,200 mcg RAE, although eggs, dairy and a varied diet cover that requirement for most people.
Remember to always discuss any vitamins or supplements with your trusted healthcare professional while pregnant or breastfeeding, or while attempting to conceive.
What are deficiency symptoms of vitamin A?
Possible signs of vitamin A deficiency may include (but are not limited to) the following:
- Night blindness
- Dry poorly healing skin and membranes
Night blindness is the classic early sign. Excess vitamin A is toxic, so do not treat guessed deficiency with megadoses.
If you are experiencing abnormal symptoms, reach out to your trusted healthcare professional as soon as possible.
Where should I store vitamin A?
For optimal shelf life, it is recommended to keep vitamin A supplements stored in the cupboard. Always make sure the bottle or container is tightly closed, and kept away from sources of light, heat and humidity.
Vitamin A data sources & further reading
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