UPDATE 5/23/17: See below – “How do you know you have a problem with vitamin A?” and “Plant Foods Highest in Vitamin A showing 12:1 beta-carotene to retinol conversion”
UPDATE 5/22/17: Regarding the conversion ratio for beta-carotene to retinol, I’d believed it was 6:1 (having gotten that figure from an anti-vegan meat enthusiast of all things, lol) and had used that ratio herein; but I’ve read elsewhere that scientists have raised the ratio to something like averaging 12:1, so I’ve revised the information below accordingly, just to be on the safe side.
Vitamin A is a fat-soluble* vital nutrient important for healthy vision, the immune system, and reproduction. *So it’s best to have a bit of healthy fat (like avocado, nuts, etc.) with your beta-carotene-rich foods to help with absorption/utilization. Vitamin A also helps the heart, lungs, kidneys, and other organs work properly.
Note: “Vitamin A” and “retinol” will be used interchangeably throughout, since they’re essentially the same. Also, this article is long and and a bit exhaustive, only because it’s good to be armed with thorough understanding when confronted by such tactics as those mentioned herein.
First, the scary story goes something like this:
“These ignorant, emotionally driven vegans believe they’re so healthy on their plant food diets and believe they don’t have to worry about vitamin A, but we robust meat lovers know better. You see, retinol is the only usable form of vitamin A and beta-carotene is a poor, weak substitute which must be converted by your body to retinol, at a ratio of twelve to one (maybe even more!). Retinol is only in animal products, while beta-carotene is in inferior plant foods. Animal liver is especially loaded with real vitamin A, and that’s why (among many other reasons) it’s imperative that we eat animal products.
Vegans are fooling themselves, see; veganism is fraught with dangers! And vitamin A deficiency is especially ominous since vitamin A is important for normal vision, the immune system, reproduction, and proper functioning of our vital organs.
So, get you some beef liver and ice-cream and chow down, after all it’s for your very survival! Forget those vegetables & fruits as good sources; you have to eat tons of that indigestible ‘food’ to get your needed retinol from converting it in your system, if you even CAN convert it! Many people cannot convert it at all, such as infants, so they absolutely must eat animals (or take vitamin A supplement)!”
So after hearing that, among all the other fear tactics, the unaware animal-respecting would-be vegan is effectively led away from veganism, angry over having been mislead by those malnourished, despicable vegans. They fall willingly into the embrace of the meat/egg/butter zealots, convinced that animal protein and fat are vital to human health. (But most any good cardiologist will tell you quite the opposite when being honest rather than opportunistic.) People become quite frightened though, convinced that eating liver and/or other animal products will save them from vision problems and all the rest. Animal ag mission accomplished.
But it gets even scarier!
“As far as infant nutrition, well, since babies cannot convert beta-carotene to retinol at all, well, babies simply must have animal sourced A, or at least a retinol supplement!”
Oh, really? Scary, yes, but it’s all based in “untruths” (to be polite).
Now, for the truth:
An adult human (male) needs something like 3,000 IU (international units) of vitamin A per day for good health, especially to protect eyesight. One large sweet potato has about 28,000 IU of vitamin A as beta-carotene. The body’s conversion ratio of beta-carotene to retinol is about 12:1. So, 28,000 divided by 12 is 2,333, almost enough usable A in just that one orange-fleshed sweet potato.
What if you’re one of the unfortunate who has impaired conversion of retinol to A? [See “Groups at Risk of Vitamin A Inadequacy” in reference 1 linked below.] The worst case scenario is with a genetic type of people (those carrying at least one T in two genes), so they have a 70% lower conversion of beta-carotene to retinol, so they only use about 30% of it. So, say one eats the equivalent of four sweet potatoes in a day. That’s 112,000 IU of beta-carotene, divided by 12 is 9,333 IU, and 30% of that is 2,800 IU. So you’re still fine. But that’s a lot of sweet potatoes (the richest vegetable source of A), so although it’s possible for this group of people to use food alone for A, they may well need vitamin A supplement to be vegan, or to drink carrot juice (which I love) often, since it is loaded with beta-carotene at 45,133 IU in just one 8-oz. glass.
How do you know you have a problem with vitamin A?
Symptoms include night blindness, dry skin, and frequent infections. People may experience these common symptoms: dry eyes, dry skin, frequent infections, inability to see in dim light, or spots in the eyeball.
Fortunately, many plant foods contain beta-carotene, such as spinach, carrots, pumpkin, cantaloupe, mangoes, apricots, cherries, red peppers, and so forth. So a variety of those foods in a day and you’re likely meeting or far exceeding your vitamin A needs. If you’re one who hates all those foods, then you’d be well advised to learn to like them or get your vitamin A elsewhere. But animal liver or cod liver oil are not necessary and it’s fairly easy to get far too much retinol from them which can lead to serious but uncommon conditions outlined in reference 2 linked at bottom. Vitamin A and beta-carotene supplements are of course available, but I don’t use them, far preferring food sources.
Here’s my minimal vitamin A intake for May 21st, for example:
1 medium carrot 10,000 IU
4 cups raw spinach 11,250 IU
1 tomato 1,000 IU
2 medium mangoes 6,000 IU
8 oz. V8 type juice 900 IU
Total 29,150 IU ÷ 12 = 2,429 IU (women’s requirement is 2,300)
And this was a low vitamin A day for me, I sometimes get much more by adding a sweet potato; so you see it’s pretty easy. Nothing all that difficult or scary about vitamin A for vegans!
As an added reassurance: Extra vitamin A, due to its being fat soluble is stored in the (healthy) liver and taken up as needed by the body. So consuming adequate amounts of A everyday is not always necessary; you can pig out on sweet potatoes one day and have enough vitamin A stored in your liver to last several days. (Actually, the liver is said to store a 1–2 year supply of vitamin A!)
Note that vitamin A as retinol is slightly impaired by heat, while beta-carotene is not so impaired; in fact, cooking carrots for 15 minutes or less makes their vitamin A even more available by breaking down the walls of the plant cells that contain beta-carotene. But, raw or cooked are both fine as long as you eat plenty and chew thoroughly if raw (or blend as in smoothies).
Only truly carnivorous animals like lions cannot convert beta-carotene to retinol at all, so they must get animal sources of retinol. That’s why these paleo activists and others are so hellbent on believing they need liver and such, since they believe humans are carnivorous omnivores. Well, quite simply, we’re not. We’re far more like self-made omnivores who do much better leaving off the animal products. And all omnivores can thrive with zero animal foods if nutritious plant foods are available. And guess what, most humans have them available, in abundance. (Thank GOODNESS for crop farmers.)
[See Table 2 in reference 1 linked at bottom for a list of several foods and their retinol content.]
“But, Babies Must Have Animal Source Vitamin A!”…
…say all these paleo and low-carb, meat industry activists out there anyways.
This is the really “scary” bit, about “infants not being able to convert beta-carotene to retinol, at all!” Oh my, that sounds like a recipe for vision problems or even blindness, and all sorts of other disastrous problems for children throughout life, unless they eat liver and animal products, right? Now, who would force a dangerous vegan diet on their beloved child out of respect for animals? Well, we’re dealing with seriously misleading fear tactics there.
Here’s the not so scary truth:
When born at normal term and breastfed by healthy moms (or, less desirably, given proper formulas), infants’ vitamin A levels are what they should be and they develop just fine and with perfectly healthy eyesight. Infants have stores of retinol in their livers from their moms, as nature intends it, as well as through breastfeeding and getting the needed colostrum from mother’s first milk.
But if there is doubt, all baby formulas contain vitamin A supplement. Do note that vitamin A pills (as opposed to beta-carotene) can be derived from fish liver oil, but many commercial vitamins are synthetic, thereby cheaper and easier to produce than natural vitamins. Non-animal vitamin A supplement is synthesized from acetone, and there is said to be no chemical difference between the purified vitamins derived from plant or animal sources and those produced synthetically (http://www.madehow.com/Volume-3/Vitamin.html).
Vitamin A deficiency is quite rare in infants in developed countries like the USA, usually occurring in rare infants with malabsorption disorders [see reference 5 linked at bottom]. Those infants’ retinol levels can be increased and maintained with enough vitamin A supplement.
In premature babies, their stores of vitamin A are lacking due to not getting adequate amounts due their short time in the mother’s womb, and their retinol levels often remain low during the first year of life. They also need careful vitamin A supplementation.
But as long as the mother is nutritionally aware and eating plenty of beta-carotene rich foods according to her needs (such as if she has conversion problems), everything should be fine. To be on on the safe side, it would follow that pregnant/breastfeeding women should get about twice as much beta-carotene as she’d need normally, which is equivalent to about four sweet potatoes, but can of course be gotten from a variety of other foods as well.
Plant Foods Highest in Vitamin A showing 12:1 beta-carotene to retinol conversion:
a) Large (7”) Sweet Potato
1 whole: 28,000 IU = 2,333 after 12:1 conversion
1 medium: 10,000 IU = 833 after conversion
1 cup chopped: 6,693 = 558 after
2 cups raw: 5,626 IU = 469
3 fruits: 2,022 IU = 168
2 cups raw: 1,134 IU = 95
Yielding 4,456 converted and totally legitimate IUs of real vitamin A, perfectly within the 2,300 (minimum) to 5,000 IUs recommended for adult women and just about twice a woman’s basic needs normally, so quite enough for a pregnant woman.
[See Table 1 in reference 1 linked below – note that “mcg RAE” roughly multiplied by 3 is your minimal IU need (after the 12:1 conversion of beta-carotene to retinol), so 900 mcg = 2,700 IU in this instance. NIH’s explanation is calculating before the conversion factor, so please don’t be confused there.]
And keep in mind that most pregnant/nursing women, whether vegan or not, take a variety of supplements or at least a multi-vitamin/mineral supplement for pregnant women, so are likely beyond fully nourished to grow a healthy baby.
Interestingly, even in “third world” or developing countries where women are often malnourished, infants have sufficient vitamin A while breastfeeding, but deficiency occurs just after they stop breastfeeding. So those children of course need much more beta-carotene rich food, or supplement. But be very careful with vitamin A supplement (as opposed to beta-carotene); too much “real” retinol can reach toxic levels and is linked to increased bone fractures in women*, among other problems…
[See references 2, 3 and *4 links at bottom for warnings about vitamin A toxicity, either from pills or from animal foods.]
Note that it’s virtually impossible to get too much beta-carotene from food, as the body only converts as much beta-carotene into retinol as it needs. So, while for adult supplements it’s safer to get beta-carotene rather than vitamin A as retinol, that’s not so good for certain groups such as smokers. Due to interactions with certain drugs and other factors, excessive beta-carotene supplementing has actually shown to increase risks for cancers in those groups (http://healthyeating.sfgate.com/much-beta-carotene-bad-you-11397.html). So again it’s best to get your A from foods rather than pills.
So, bottom line regarding the baby retinol scare: The equivalent of one large sweet potato and a big healthy dark green salad with carrot and a couple of mangoes (just for example) per day is all most women need to maintain healthy vitamin A levels throughout pregnancy and beyond and to provide plenty of retinol for their babies through six months old. If born prematurely, most everyone already knows babies can benefit from supplements, including safe amounts of vitamin A.
A normal baby’s need for vitamin A is about 1,200 IU daily, about half that of an adult woman, so after a baby is weaned, just two cooked carrots at 18,400 IU divided by 12 leaves him/her with with about 1,500 IU usable vitamin A. As the child grows of course, the nutritional needs rise [see Table 1 in reference 1 linked below – again, remember “mcg” multiplied by 3 is your IU number after the 12:1 conversion]. After 6 months of age, or after weaning, all babies can do fine with only plant sources of A. So vegan babies are quite well off as long as their parents are nutritionally aware, same as any other babies but even better, since they’re not brought up depending on animal abuse and slaughter.
Aside from all that above, most pregnant/nursing women, as well as many other people, take multiple vitamin supplements including vitamin A (as retinol or beta-carotene). I don’t…only take very few supplements…as I feel much safer getting needed nutrition from plant foods. Plant foods are antioxidants and fiber rich (life preserving, cancer preventative, heart healthy), unlike animal foods, and this all further concurs with my being rightfully and passionately opposed to slaughterhouses and all the rest of such terrible human behavior.
So, what’s all this fear-mongering about “real” vitamin A from animal foods versus “blindness causing fakery” from plant foods (etc., etc.)? Well, it’s all in the interests of the animal agriculture industry and all of its offshoots, naturally. Don’t be fooled. Study the issues yourself using objective, legitimate sources, such as the following…
1) All about vitamin A: https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/
2) Dangers of too much “real” retinol: http://www.mayoclinic.org/drugs-supplements/vitamin-a/safety/hrb-20060201
3) More real dangers of overdosing on retinol: http://www.nytimes.com/health/guides/disease/hypervitaminosis-a/overview.html
4) Increased bone fractures in women from too much retinol: https://www.ncbi.nlm.nih.gov/pubmed/11754708
5) Malabsorption disorders in infants: http://emedicine.medscape.com/article/931041-overview#showall
6) Yes, carrots, etc., are recommended for babies: https://www.babycenter.com/0_vitamin-a-in-your-childs-diet_10324693.bc
This article provides information that should not take the place of professional advice. I am not a nutrition or health professional but am sharing what I’ve learned through experience and from what I trust are good sources in regard to my own nutrition. If you have concerns, I encourage you to talk to a (vegan friendly) registered dietitian or other trusted professional about your dietary needs.