What is Vitamin A?
Vitamin A is a fat soluble vitamin, which is either found ready formed – for example in animal products such as meat and dairy – or as pro-vitamin A, beta carotene, in fruits and vegetables. Beta carotene is then converted into Vitamin A in the body, with the help of the hormone thyroid.
Vitamin A is crucial for many functions, such as vision, reproduction, breastfeeding and in maintaining healthy skin, teeth and bones.
Liver is a great source of vitamin A. For beta carotene, the more intensely coloured the fruit or vegetables – the higher the amount of beta carotene it provides. Supplements wise, cod liver oil is an excellent source (just make sure you check the ingredients and choose a good quality supplement).

Vitamin A Toxicity
If you don’t get enough vitamin A you can experience immune and vision issues – but conversely it is equally problematic getting too much. In fact excess vitamin A has even been shown to result in birth defects. Excessive consumption of beta carotene is not so serious, but it will make your skin turn yellow or orange, which would look rather alarming! Fortunately the skin will return to it’s normal colour once intake of beta carotene is reduced.
Another issue with excessive levels of vitamin A, are that it appears to reduce the bodies ability to utilise Vitamin D. As people tend to be deficient in Vitamin D (perhaps more so than Vitamin A), this could be a real problem. As with so many vitamins and minerals, it appears having a good balance is crucial.
Best Natural Food Sources of Vitamin A
When aiming to boost your vitamin A levels through real food, animal-based sources are by far the most effective. This is because they provide the active form of vitamin A, known as retinol, which your body can use immediately without needing to convert it. Organ meats top the list, with liver being the most concentrated source. A small portion of beef or lamb liver just once a week can cover your entire weekly requirement.
Other excellent animal-based sources include:
- Egg yolks (especially from pasture-raised hens)
- Butter and ghee from grass-fed cows
- Oily fish like sardines and salmon
- Full-fat dairy products (if tolerated)
On the plant side, beta carotene provides a precursor to vitamin A and is found in vibrant orange, yellow, and dark green vegetables. However, conversion rates vary between individuals, depending on factors like thyroid function, genetics, and overall diet. The richest sources of beta carotene include:
- Sweet potatoes
- Carrots
- Pumpkin
- Dark leafy greens like kale and spinach
- Butternut squash
How Vitamin A Supports Your Immune System
Vitamin A plays a central role in maintaining a strong immune defence. It helps form the mucous membranes lining your respiratory tract, gut, and urinary tract—your body’s first line of defence against invading pathogens. These mucous layers rely on vitamin A to stay moist, thick, and effective at trapping and removing viruses and bacteria.
In fact, one of the earliest symptoms of vitamin A deficiency is a higher susceptibility to colds, flu, and respiratory infections. Without adequate vitamin A, your immune system struggles to activate T-cells, which are essential for fighting off illness.
This is particularly important for children, the elderly, and anyone with an autoimmune condition. Ensuring your diet includes sufficient amounts of bioavailable vitamin A can help keep your immune response robust and reduce recovery time from illnesses.
Vitamin A and Skin Health
Vitamin A is often referred to as the “skin vitamin” for good reason. It supports cell turnover and regeneration, which are vital for healthy skin tone and texture. A deficiency can lead to dry, rough, or flaky skin, and in more extreme cases, a condition known as follicular hyperkeratosis, where the skin becomes thick and bumpy—particularly on the arms and thighs.
Topical forms of vitamin A, such as retinol, are commonly used in skincare, but nourishing your skin from the inside out with food sources can be just as powerful. Many people who increase their intake of liver, eggs, and colourful vegetables report clearer, smoother, and more resilient skin over time.
Can You Absorb Enough Vitamin A on a Plant-Based Diet?
While beta carotene in plants can be converted into vitamin A, the process is not always efficient. Some people carry a genetic variant that significantly reduces their ability to convert beta carotene into active vitamin A. This is particularly relevant for those following a vegetarian or vegan diet, where animal-based sources are excluded entirely.
For individuals with thyroid imbalances, digestive issues, or poor liver function, conversion can be even more impaired. In such cases, relying solely on plant sources may not be enough to meet your needs, making it essential to monitor your health and consider testing your nutrient status through a qualified practitioner.
Testing and Balancing Vitamin A Levels
If you're unsure whether you're getting too little—or too much—vitamin A, consider having your blood levels tested. A holistic practitioner or integrative GP can assess both your vitamin A and vitamin D levels to see how they’re interacting. Remember, it’s all about balance. You don’t want one fat-soluble vitamin to crowd out another.
Some signs that your vitamin A levels may be low include:
- Dry eyes or night blindness
- Increased frequency of colds or infections
- Rough, dry, or peeling skin
- Difficulty conceiving or irregular cycles
On the other hand, symptoms of vitamin A excess may include:
- Headaches and nausea
- Bone pain or fragility
- Dizziness
- Peeling or cracked lips
Safe Supplementation Practices
For those considering a vitamin A supplement, especially in the form of cod liver oil, it’s critical to check the label and dosage. Many high-quality cod liver oils now balance their vitamin A and vitamin D ratios to reflect ancestral diets more closely. Still, it’s easy to overdo it, particularly if you’re also eating liver or fortified foods.
When supplementing, less is more. A rotational approach—such as taking cod liver oil a few days per week and eating liver once every 7 to 10 days—can help avoid both deficiency and toxicity. And as always, food should come first. Supplements should fill in the gaps, not replace whole, nutrient-dense meals.
Vitamin A and the Paleo Diet
One of the great benefits of following a paleo diet is that it naturally includes many of the best sources of vitamin A. From liver pâté and slow-cooked beef cheeks to roasted sweet potatoes and hearty kale salads, it’s easy to build meals that support optimal intake without needing synthetic vitamins or processed foods.
Rather than counting micrograms or tracking conversions, a Paleo approach allows you to eat intuitively from a wide variety of foods, trusting that a nose-to-tail and plant-diverse diet will deliver what your body needs—when combined with adequate sun exposure, rest, and movement.
Are You Getting the Right Balance?
In the end, it’s not just about vitamin A in isolation. The body works as a system, and nutrients interact with each other in complex ways. Keeping your fat-soluble vitamins in balance—A, D, E, and K—is key to ensuring each one functions optimally. Rather than megadosing or avoiding these nutrients altogether, aim for moderate, food-based intake and regular testing where possible.
If you’ve never tracked your vitamin A intake or tested your levels, it might be worth exploring. Real food is powerful—and when used wisely, it can be one of your best tools for lifelong health.
Have you had your levels checked? How were they? Are you concerned about toxicity? Please share your experiences in the comments below.