DNA Digest: Vitamin A
Today, we're going to talk about a vitamin that's essential for healthy vision and immune function: vitamin A. Did you know that our genes can play a role in how we absorb and use this important nutrient? In this blog, we'll explore the basics of vitamin A, the BC01 gene, and what we need to do to ensure we're getting enough. So, let's get started!
What is Vitamin A?
Vitamin A is a fat-soluble vitamin that plays a critical role in maintaining healthy eyesight, skin, and immune function. It is found in a variety of animal-based and plant-based foods, including liver, fish, eggs, dairy, and colourful fruits and vegetables.
What is the BC01 gene?
The BC01 gene encodes the enzyme beta-carotene oxygenase 1, which is responsible for converting beta-carotene (a precursor to vitamin A) into the active form of vitamin A. Variations in this gene can impact how efficiently the body converts beta-carotene to vitamin A.
Why is the BC01 gene important?
Studies have found that individuals with certain variations in the BC01 gene may require higher levels of vitamin A to maintain optimal vitamin A status. This is because their bodies may have a harder time converting beta-carotene into the active form of vitamin A.
How much Vitamin A do we need?
The recommended daily intake of vitamin A varies by age and sex. For adults, the recommended intake is 900 micrograms of retinol activity equivalents (RAE) for men and 700 RAE for women. It's important to note that excessive intake of vitamin A can be toxic, so it's essential to stick to recommended levels.
What are some sources of Vitamin A?
Vitamin A can be found in animal-based foods like liver, fish, eggs, and dairy, as well as in plant-based foods like sweet potatoes, carrots, spinach, and kale. Some foods, such as breakfast cereals and plant-based milks, may also be fortified with vitamin A.
What are the symptoms of Vitamin A deficiency?
Symptoms of vitamin A deficiency can include dry eyes, night blindness, and a weakened immune system. In severe cases, it can lead to blindness and other serious health complications.
What can impact our Vitamin A status?
In addition to genetic factors, lifestyle factors can also impact our vitamin A status. Individuals with diets low in animal products (ie. vegans or vegetarians) or those who don't eat many colourful fruits and vegetables may be at higher risk of vitamin A deficiency.
References
- Gottesman ME, Quadro L, Blaner WS. Studies of vitamin A metabolism: The role of BCO1. Am J Clin Nutr. 2016;104(Suppl 3):917S-921S. doi:10.3945/ajcn.116.139758
- Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academies Press (US); 2001. Accessed June 24, 2021.
- Lind T, Jakobsen J. β-Carotene in animal feeding. Acta Agric Scand Sect A. 1998;48(4):207-215. doi:10.1080/09064709809362377
- Ross AC, Manson JE, Abrams SA, et al. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab. 2011;
