According to Dr. Ray Peat, vitamin A is very important for your health — it has anti-aging, anti-acne, and anti-estrogenic properties. For more on how to eat and supplement to support thyroid and hormonal health, see my book How to Boost Metabolism with Food and my Metabolic Nutrition Mastery course. Learn about vitamin A supplementation in this blog post.
What does vitamin A do in the body?
According to Dr. Ray Peat, vitamin A is essential for a healthy hormonal balance as well as good eye, teeth, skin, and immune function.
Vitamin A improves immunity
Getting enough vitamin A is essential for good immune function, as vitamin A is necessary for the integrity of mucous membranes and thereby the protection of the body from its outside environment.
Vitamin A helps fight stress and inflammation
Vitamin A is necessary for the body's ability to produce its protective anti-aging and anti-stress hormones pregnenolone and progesterone — the kind of pro-metabolic lifestyle that keeps these hormones elevated is what I teach in my book Roadmap to Metabolic Health. These hormones are produced in large amounts in youth and are thus called youth-associated hormones.
The body uses vitamin A, cholesterol, red light, and thyroid hormone to produce progesterone and pregnenolone.
Progesterone and pregnenolone protect the body from the negative effects of stress and inflammation. You can learn more about supplementing these hormones in my Hormone Rebalance Intensive™ course.
Anti-estrogenic effect of vitamin A
Vitamin A has anti-estrogenic properties.
As I explain in detail in my Thyroid Transformation Course, estrogen is both inflammation- and aging-promoting.
Vitamin A protects the body from the negative effects of estrogen excess.
Symptoms of vitamin A deficiency
Symptoms of vitamin A deficiency include:
- Skin problems such as dry skin, acne, and dandruff.
- Problems with night vision.
- Hormonal issues including estrogen dominance and high prolactin.
- Immune system failure, making you more prone to infections.
What foods are rich in vitamin A?
Several foods contain vitamin A. From highest to lowest content, here are some foods which are rich in vitamin A and also part of my thyroid-supporting diet.
Cod liver, turkey liver, beef, pork and fish liver, chicken liver, ghee, butter, cheese, eggs, and milk.
With a diet high in these foods, most people get enough vitamin A. However, a high thyroid function can increase your need for vitamin A.
My thyroid-promoting diet is based on Dr. Ray Peat's nutritional research. The Ray Peat diet is explained in detail in my Thyroid Transformation Course.
How much vitamin A do I need?
Your metabolic rate determines how much vitamin A you need. According to Dr. Ray Peat, the higher your thyroid function, the more vitamin A your body needs.
On the contrary, if you have low thyroid function, using too much vitamin A can suppress your metabolism further.
Vitamin A and low thyroid function
If you have low thyroid function, you need to be careful not to overdose on vitamin A. Using the foods mentioned above, which are rich in vitamin A, will provide enough vitamin A without the risk of overdosing.
Vitamin A and high thyroid function
If you have high thyroid function — which is often the case if you are on thyroid replacement therapy — for a full guide to thyroid medication options, see my book How to Use Thyroid Medication and my Thyroid Recovery & Renewal course — — supplementing with vitamin A might be necessary in order to avoid the symptoms of vitamin A deficiency mentioned above.
Types of vitamin A supplements
If you need a vitamin A supplement, there are several things you need to be aware of.
First of all, I recommend using a real vitamin A product, meaning retinol instead of the precursor to vitamin A called beta-carotene, which is often promoted as a vitamin A supplement.
Why beta-carotene is not recommended
Beta-carotene supplements are often sold as vitamin A, but very little of the beta-carotene is actually converted to vitamin A.
Secondly, beta-carotene has a similar structure to polyunsaturated fats, which inhibit thyroid function.
You can learn more about which foods and substances inhibit thyroid function in my Thyroid Transformation Course.
The best vitamin A supplement
In my Supplement Solutions Course, you can learn what vitamin A (retinol) supplements I recommend and get different dosage examples for different vitamin A deficiency symptoms.
My Supplement Solutions Course contains a collection of high-quality vitamins, minerals, and herbs that are helpful for supporting good thyroid function and a healthy hormonal balance.
Frequently Asked Questions
Why is vitamin A important for thyroid health?
Vitamin A is essential for the production of the body's protective hormones — progesterone and pregnenolone — which require vitamin A, cholesterol, red light, and thyroid hormone to be synthesised. It also has anti-estrogenic properties, which is important because excess estrogen suppresses thyroid function. Getting enough vitamin A therefore supports the whole hormonal system, including the thyroid gland — something I explore in detail in my Hormone Rebalance Intensive™.
What are the symptoms of vitamin A deficiency?
Common symptoms include dry skin, acne, dandruff, poor night vision, hormonal imbalances such as estrogen dominance and high prolactin, and a weakened immune system that makes you more prone to infections.
Should I take a vitamin A supplement or get it from food?
For most people, a diet rich in animal-source vitamin A — liver, eggs, butter, ghee, cheese, and milk — provides sufficient vitamin A without risk of overdose. However, people with high thyroid function or those on thyroid replacement therapy may need additional supplementation. Always use retinol (real vitamin A), not beta-carotene, which is poorly converted and can suppress thyroid function. I cover the full picture of thyroid-supporting supplementation in my Nutritional Supplements course.
Is beta-carotene a good source of vitamin A?
No. Beta-carotene is often marketed as vitamin A, but only a very small fraction is actually converted into active vitamin A (retinol) in the body. Additionally, beta-carotene has a structural similarity to polyunsaturated fats, which can inhibit thyroid function. I recommend avoiding beta-carotene supplements and choosing retinol instead.
Can you take too much vitamin A?
Yes — if you have low thyroid function, excess vitamin A can further suppress your metabolism. This is why food sources are generally safer than high-dose supplements for people with hypothyroidism. If you have high thyroid function or are on thyroid replacement therapy, your need for vitamin A increases and supplementation may be appropriate.
