Are Vitamin A supplements helpful or harmful?
Nutrition PhDc Answer: Vitamin A supplements can be both helpful or harmful, but the harms from vitamin A supplements can be severe. People often assume that supplements are safe because they are natural, but vitamin A in particular can cause liver damage that doesn’t show up for years. What you take today, if it’s too much for your body, might not cause symptoms for several years — damage that may not be able to be undone.
Bottom line: Vitamin A is an important nutrient that comes from many food sources. It’s rarely risky from foods. But when you consume supplement forms (like retinol vitamin A or cod liver oil), you always have the potential to consume more than your body needs or can handle. Some nutrients can cause symptoms of excess quickly, but fat-soluble vitamins like vitamin A build up in the body. You won’t know you’ve over done it until weeks, months, or even years later. Dietary supplements are also not regulated in a strict way like pharmaceutical medicines. A supplement may say it's one dose, but it could contain more (sometimes significantly more) than the label states.
What are the risks of too much vitamin A?
- It can cause liver damage. In kids, whose livers are smaller, this damage can be more severe.
- It can stimulate the cells that break down bones, while suppressing the cells that build bones. This is especially concerning in kids, whose bone development is vital for long-term health, as well as in people who are past their 30s, when bone density can start to decline (and be lost for good).
- It can cause birth defects when supplemented in the active retinol form. These can't be undone, and can be very severe. People who are pregnant or could be should not take vitamin A retinol supplements unless there is a strict medical reason and intake is monitored by a medical provider with expertise in this high-risk area.
- It can disrupt the balance of other fat-soluble nutrients, like vitamin D, vitamin K, and vitamin E. The immune system and the body as a whole relies on balance. Too much of a good thing can become a dangerous thing, and can create a cascade of other bad reactions and imbalances.
Are the risks overstated?
It depends on how they are stated, but the risks outlined in this article are based on multiple reviews of the most current evidence. Factual Wellness has no industry conflicts or sponsors; no one is controlling the answers published here. When getting information about vitamin A (or any nutrients), it's very important to ask yourself if it may be biased and how. Can the person recommending it directly or indirectly make money from you buying vitamin A supplements? That's a red flag that is too often overlooked.
The right to make money by promoting products does not surpass your right, as a consumer, to ensure that the information you receive about something that has the potential to negatively impact your health is based on balanced, accurate, and non-biased information. Money can cloud someone's perspective. Even if they sell with integrity, they are still selling, and their livelihood depends on your belief in their claims. That is motivation to make the sale, which in wellness, often means overstating possible benefits and downplaying possible risks.
What about vitamin A supplements and immune support?
Vitamin A is needed for a normally-functioning immune system. But you can get enough from food sources. You also need lots of other nutrients for a healthy immune system. The hyperfocus on a single nutrient is always harmful, because the body doesn’t function in extremes, it relies on balance. Also: you don’t want to harm your liver to supposedly boost your immune system.
What about measles and vitamin A?
If you’re considering vitamin A because of the current measles outbreak, there’s a lot of claims being made all over the place. Here’s how to vet your information source:
- Will they financially benefit from telling you to take or buy vitamin A?
- Do they have personal knowledge of your health, your other medications, and your conditions?
- Do they have legal responsibility to give you safe advice?
- Are they qualified to give you personal medical advice, or are they providing information with an attached FDA disclaimer that they make no claims to heal, cure, prevent, or treat any conditions?
- Do they have a platform or popularity based on a specific stance, such as advocating against medications or for supplements and natural health as the "best" way?
- Do they have advanced degrees in the field (in this case, nutrition science) to fully understand the ramifications that come from super-dosing a single nutrient?
What if my healthcare provider is against all supplements?
It’s understandable if you want to consider supplements, and your provider is against them across the board, to decide on your own whether you’ll take them or not. However, when providers urge caution with supplements, it’s often for several reasons.
Sometimes they may seem overly cautious or unfounded. However, fat-soluble vitamins can cause actual toxicity (the kind that can land you in the hospital, cause permanent organ damage, and worse). In this case, the risks cannot be overstated.
Vitamin A is not a superpower for amped up instant sickness defense
Blasting your body with high-dose vitamin A will not coerce your immune system to magically kick into gear. Fat-soluble vitamins don’t change your body’s immediate reactions; they accumulate over time. So if you get sick today, and take a vitamin A supplement for the first time today, the reaction time for your body to get and use that vitamin A is not today or tomorrow or even next week.
If you are taking vitamin A proactively for an eventual time in which you may be exposed to sickness, there are still toxicity concerns. Even lower amounts, taken consistently over time, can overload the liver. Beyond that, having adequate vitamin A stores does not prevent infection of any type. In some people, it could theoretically help the body address an infection — but only if it's in balance with all of the other essential vitamins and minerals. However, in others, vitamin A may do nothing to alter a potentially serious or deadly infection, or could trigger its own harm.
Why does the World Health Organization recommend vitamin A for measles then?
The World Health Organization has recommendations for vitamin A and measles in other countries because there, a majority of vitamin A comes from carotenoid sources (meaning, it may not convert to cause high enough active vitamin A levels).
In the U.S., a majority of vitamin A that comes from foods is the active form. Vitamin A supplementation in the U.S. is much more likely to cause excess, not adequacy. This is partly because vitamin A in retinol form absorbs very well — potentially 75% to 100% of what you take in could be absorbed and stored.
Mia McNew, MS, PhDc
