No, in my opinion vitamin A supplements are not safe. And again no, in my opinion whole food plant-based vegans do not need vitamin A supplements. This is a rare example of a straightforward answer to a nutritional question :-)
Vitamin A (retinol and other retinoids) is a fat soluble vitamin and can accumulate in the body, particularly in the liver, and can reach toxic levels if obtained from a supplement or if too much preformed vitamin A is obtained from animal sources such as liver and cod liver oil for example. Curiously, the most toxic concentrated source of preformed vitamin A is polar bear liver! :-)
However, obtaining provitamin carotenoids (such as beta-carotene) from plant foods has not been shown to have any toxic or cumulative side-effects, except for perhaps turning the skin slightly orange coloured :-) I want to stress that the best place to obtain all the provitamin carotenoids is from food, particularly green and yellow (and orange) vegetables and fruits. I stress this because there is some indication that obtaining beta-carotene from supplements (if you are a smoker) can increase the risk of lung cancer.
There are around fifty carotenoids in plant foods (including beta-carotene) which are measured in ‘retinol activity equivalents’ (RAE) and we need to obtain approximately 1.3 mg of RAE per day (although the recommended daily amount varies from country to country). Two of the best sources of carotenoids are sweet potato and spinach. A single medium sweet potato (with the skin) or a cup of cooked spinach will provide the required daily amount.
Some of the consequences of excess preformed vitamin A consumption are:
- increased risk of bone fracture,
- liver damage,
- vision problems
- hair loss,
- respiratory infection,
- kidney damage due to excess calcium,
- increased intracranial pressure,
- coma, and even death.
Although many of these risks are the result of sudden or acute increases in preformed vitamin A consumption, regularly eating or supplementing significantly in excess of three milligrams per day (UL) of preformed vitamin A can still lead to many of these injuries and disease outcomes over time. The Upper Limit for vitamin A consumption is even less for teenagers and children.
These are some of the reasons why I believe that preformed vitamin A (and possibly even beta-carotene) supplements are not safe, and are certainly not necessary for those who follow a 100% whole food plant-based diet including WFPB vegans.
If you are 100% whole food plant-based or WFPB vegan, you may be concerned about some reports indicating that a certain gene BCO1 reduces the synthesis and absorption of active vitamin A from plant sourced provitamin A. These reports appear to be based on observational studies and as far as I can tell, the link between the gene and the variable conversion rate from provitamin A has not been proven.
Personally, I think that the variation in conversion and absorption among different people is due to a number of other factors including; the type of plant foods consumed, how they were cooked, whether they were organic, whether or not the people consuming them were also eating the standard UK diet (SUK) or the standard American diet (SAD) i.e. garbage, and whether the study subjects were taking any medication which would interfere with absorption and so on.
Provitamin A conversion and absorption can be significantly enhanced by including some whole food plant-based fat with the carotenoid-containing foods during consumption. For example; avocado, walnuts, chia seeds, whole olives, or tofu. Developing and nurturing a healthy gut microbiome will also help :-)
Bear and Potato images are public domain