Beta Carotene Conversion – Are You Making Enough Vitamin A?

Up to 55% of people might not be!

Vitamin A (retinol) is an essential nutrient that we need to get from our diets.  It is needed for healthy skin, digestion, immunity and for vision. Many vegetarians and vegans rely on converting beta carotene to vitamin A, but new research shows that 55% of people might not be making this conversion properly.  

Vitamin A is also called retinol, the name comes from the fact that a lot of this nutrient can be found in the retina of the eye.  For decades nutritional science has stated that the human body can convert a brightly coloured pigment, called beta carotene found in fruits and vegetables, into retinol and it has been considered a vitamin A precursor. So why is this conversion suddenly a hot topic in nutrition?



Beta Carotene

For quite some time beta carotene has been presented as the recommended way to meet most, if not all, of our vitamin A requirements due to concerns dating from the 1980s about possible toxicity from excess retinol, so called ‘hyper-vitaminosis A’ which happens when storage space in the liver fills up and the vitamin starts to spill out, into the rest of the body, causing problems like swelling. Beta carotene has been thought to have the advantage of only being converted into retinol when it is needed in the body, and so has been presented as the safer option. In particular this recommendation has been fed to women of reproductive age due to concerns about excess retinol harming the foetus, causing malformations such as tiny ear canals, facial disfiguration or a cleft lip and palate. Until only very recently you would never find much, if any, retinol in a multi-vitamin tablet aimed at pregnancy or for fertility. On top of this issue many vegans or vegetarians choose beta carotene as their source of vitamin A over retinol as it comes from plant-based foods and retinol is thought to only be found in animal products such as liver, eggs, fish and dairy.


The Genetic Lottery of Beta Carotene Conversion to Vitamin A

However the science of nutrition is moving at a fast pace and it has recently been brought to light that the conversion of beta carotene varies considerably among people. Fourteen years ago researchers in California discovered that only 45% of people could achieve adequate vitamin A status from beta carotene alone (Lin et al, 2000). Although this was only a small study on 11 men, this triggered further research on this topic across the globe. At the same time the studies on retinol toxicity also started to be questionned.  Almost ten years later researchers from Newcastle University (Lietz et al, 2009) discovered that the reason behind conversion variation is genetic and linked to the Bcmo1 gene. Two genetic variants of this gene have been identified and it was confirmed that those people carrying these variations have a reduced ability to make the conversion. Their requirement for vitamin A may be increased.  There are similar stories with other nutrients, such as with vitamin D, and with the MTHFR gene which converts folate to an active form so that it can be used by the body.  The lottery of genetics is fascinating and learning about your own ancestral information and carrier status can give great insights into your well-being and health concerns.


By Katie Clare
Registered Nutritional Therapist


True Food Supplements

At inSpiral we are now on the look-out for a pure, natural, vegan source of retinol and will bring one to our webshop as soon as we can.  We believe in true food, pure supplements that are as close to nature as possible.  We investigate everything that we sell on our webshop in great detail to bring you the best products that live up to our vision. inSpiral has recently started selling a vegan vitamin D3, exclusive in that the D3 comes from an organic plant source, called a Lichen, and not an animal-based source.  We are very proud of this. We also offer a vegan EPA supplement, the beneficial type of Omega 3 oil that is almost impossible to find in plant foods.  Instead of coming from fish oils this EPA comes from algae. We have a live, fresh, dairy free, lactic acid-rich,probiotic, liquid drink, Symprove, which we believe is the strongest and most efficient probiotic available on the market.


We bring to you a great, raw, vegan Protein Powder made from brown rice which has been holistically bio-fermentated and combined with sprouted endosperm and bran to conquer the challenge of a perfectly balanced, vegan, amino acid profile.  It is high in lysine, a nutrient that other vegan protein powders are often lacking in.  Our Sunwarrior protein powder really is awesome!  Check out our Five Alive green super foods powder, which we believe is the best on the market – and trust us, we did a look of research into them!

Sunwarrior Raw Vegan Protein: Natural 1

We have compiled our own collection of the best super foods on the planet

Finally watch this space for an exciting range of multi vitamins that will be arriving very soon.



Lietz et al (2013) Two common single nucleotide polymorphisms in the gene encoding beta-carotene 15,15’-monoxygenase alter beta-carotene metabolism in female volunteers. The FASEB Journal.  DOI: 10.1096/fj.08-121962.  Available at Accessed: 1st September 2013

Lin et al (2000) Variability of the conversion of beta-carotene to vitamin A in women measured by using a double-tracer study design. Am J Clin Nutr. 2000 Jun;71(6):1545-54.   Available at    Accessed 1st September 2013


Photo Credits

Vitamins! by Bradley Stemke/ CC BY

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