nice bullshit again TheAwakening vegan propaganda alt.
Contrary to popular belief, plant foods are lousy sources of vitamin A. In fact, they contain no vitamin A at all! Instead, they contain carotenoids, which we must then convert into retinol, the form of vitamin A our bodies can use. This is 12 to 24 times more difficult than obtaining retinol from animal foods. According to a 2013 review article in the Journal of Health, Population and Nutrition, this helps to explain why childhood blindness due to vitamin A deficiency is rampant in dozens of developing countries, particularly in Africa and South-East Asia:
“Poor bioavailability plays a predominant role in the development of [Vitamin A deficiency] among communities that mainly rely on plant-based foods.” [Akhtar S et al 2013 J Health Pop Nutr 31(4)]
Fortunately, vitamin A deficiency in the U.S. and other developed countries is very rare, due to the abundance of animal foods and because many processed foods are fortified.
When most people think of vitamin K they think of vitamin K1, which is abundant in many plant foods, but vitamin K2 is just as important and often overlooked. Vitamin K2 is confusing because it comes in many forms, but the essential form we need is called MK-4. In the brain, MK-4 is required to build critical cell membrane components called sphingolipids, as well as to support the overall health and function of brain cells.
The MK-4 form of vitamin K2 only exists in animal foods. The body can convert a little bit of K1 into MK-4, but not nearly enough to fully meet our needs. Therefore, savvy vegans turn to natto (fermented soy), which contains a bacterial form of vitamin K that our bodies can turn into MK-4 a little more easily.
Vegan diets contain virtually no vitamin B12, and severe, prolonged B12 deficiency is fatal. Most vegans and vegetarians are aware of this danger and either take supplements or consume fortified yeast (unfortified yeast doesn’t naturally contain any vitamin B12). Unfortunately, deficiency is still far more common than it should be, with some studies finding that as many as 86% of adults (regardless of chosen diet) are deficient. Researchers report wide ranges of values, but overall, vegetarians tend to have lower B12 levels than omnivores, and vegans on average tend to have the lowest B12 levels.