I am not afraid of being hit by a car. That’s not to say that I would want it to happen; it’s just not something that I live in fear of. Most of the time, I don’t even think about the possibility. Instead, when the situation warrants, I take precautions because I recognize that being hit by a car can be deadly. Even when it’s not deadly, recovery from the injuries can be painful, time consuming, and expensive. Therefore, I don’t play in the freeway. I look both ways before crossing the road. Basically, I am careful to avoid situations that would increase the likelihood of my being hit by a car.
And I am not afraid of being infected with SARS-CoV-2 and contracting Covid-19, but it’s not something I would particularly want to happen any more than I want to be hit by a car. I recognize that the disease can be deadly, and even when it’s not, recovery can be painful, time consuming, and expensive. So I take reasonable precautions. Basically, I am careful to avoid situations that would increase the likelihood of my being hit by disease.
There are times that it might be safe to play in the road. For instance, when I was young, we lived on a cul de sac. It was common for all the neighborhood kids to play in the road – running races, playing tag, kick-the-can, red-rover… While playing, we all kept a look out; if a car turned onto our road, everyone shouted “CAR” and dashed into the nearest yard. That was long ago. I no longer live on a cul de sac. Where I live now, the speed limit is 50 and nobody drives that slowly. It would be foolish for kids to play in the road here. Circumstances can affect what’s safe and what isn’t. Cul de sac – maybe safe. Major thoroughfare? Not so much.
Likewise, in disease prevention, circumstances can affect what’s safe behavior and what isn’t. People who are young and healthy, eat a perfectly nutritious diet, and have a robust immune system might feel comfortable in groups of germy people – just like I was comfortable playing in the road as a child. However, there are people who have health considerations that make it a bad idea to engage in risky behavior.
And guess what? You don’t know just by looking at someone what their circumstances are. That person who is staying home instead of getting together with friends? Maybe that person has asthma. Or diabetes. Or has another health condition that means always taking extra precautions to avoid germs. People should not need to divulge their medical history to others to avoid ridicule, and should not have to justify why they are taking steps to stay healthy – steps, by the way, that they may well have discussed with their team of physicians long before the events of 2020 ever hit. Other circumstances are at play, too. In some industries, if an employee gets sick, the county can shut down the business for a month. One sick individual can put hundreds out of work. It’s prudent for people to be cautious in their interactions and avoid those who are not careful about avoiding germs.
This year, I am having a peaceful Thanksgiving at home. For the first time in over thirty years, nobody is invited to join us. I will not be sad nor alone. I’ll be thankful for family who understand. Some of the folks who might have come have been gathering in groups, eating at restaurants, and choosing to live as if China did not let loose yet another disease on our world. That is their prerogative. For myself, I am choosing not to play in the freeway. That doesn’t make me fearful. It makes me prudent.
Technology is great. A couple taps on my phone lets me confirm medical appointments, check test results, or even communicate with my doctor. It seems incredibly efficient for my doctor to be able to make notes when reviewing lab results and not have to task someone to make phone calls. Just like that, I saw the note:
RECOMMEND ADDING EXTRA 1000 IU OF VITAMIN D TO DAILY REGIMEN
Since I could see the lab’s numbers, that recommendation wasn’t really a surprise. Vitamin D might be easy to get in the tropics, but deficiency is pretty common in the rainy Pacific Northwest since the best way to get Vitamin D is from sun exposure and we don’t have a lot of sunshine. So how do we get Vitamin D? And how much do we need?
Vitamin D is primarily synthesized in our bodies based on exposure to sunlight. Think of it like photosynthesis for people (thankfully we don’t turn green!). Both the liver and the kidneys play a part. But if we’re missing the initial sunshine step, it’s pretty difficult for the kidneys and liver to do their part. Although it’s theoretically possible to get Vitamin D through our diet (our liver & kidneys do the same hydroxylations whether our Vitamin D is acquired through diet or sunshine), there aren’t that many dietary sources. Foods containing vitamin D include fish, eggs, UV mushrooms, and pork. That’s a pretty short list. I’m not counting fortified products, since the whole point is to find nutrient-dense foods instead of taking supplements. Hiding supplements in the food doesn’t change the fact that they’re supplements instead of naturally-occurring. Plus the fact that the foods they add Vitamin D to are mainly dairy products, ensuring that people who don’t get calcium from dairy also don’t get Vitamin D. But if you consume dairy products, you can add that as a Vitamin D source, too.
So What Does Vitamin D Do for Us?
Vitamin D does more than just prevent rickets in growing kids. It reduces inflammation (!), modulates cell growth, helps us metabolize glucose, affects immune function, and helps build strong teeth.
A major job of Vitamin D is to help us absorb calcium. We can take all the calcium pills we want, but if we’re not getting enough Vitamin D, the calcium is not going to do much good – and our meds can affect things further. For instance, prednisone interferes with Vitamin D. Everyone taking DMARDs is at increased risk for osteoporosis, so metabolizing calcium is extremely important, which means that Vitamin D is important. People taking Disease Modifying Anti-Rheumatic Drugs need to be particularly careful to get enough Vitamin D so that their calcium is properly absorbed or they could end up with soft bones. Who needs more problems?
But there’s more. There is a clear link between MS and low 25(OH)D levels. Will future studies show a link to other conditions? Studies are still underway because data from previous studies is unclear. There could be a link between low Vitamin D and cardiovascular disease (which is already a risk for people with autoimmune diseases). The data on the link between Vitamin D and cancer is conflicted, but it appears that both too little and too much might increase the risk of cancer, and that Goldilocks-right-in-the-middle amounts might decrease mortality in people who get cancer despite having good Vitamin D levels. There are also studies on a link between low Vitamin D and type 2 diabetes. Another study seems to indicate that overweight people can increase their Vitamin D levels by losing weight, the thinking being along the lines of D getting trapped in the outer fat cells – losing that fat then makes the D available to metabolize. It’s fascinating.
Do We Really Need 15 mcg Per Day?
There is a tidy little chart listing US Recommended Dietary Allowances that says everyone should consume 15 mcg a day until age 70, when it goes up to 20 mcg. But then there’s the fine print. That’s dietary Vitamin D assuming minimal sun exposure. Those getting plenty of sunshine on their skin wouldn’t need as much Vitamin D from their food.
On the other hand, not everyone agrees with the US RDAs. Only 10 mcg are recommended in the UK.
Labs Can Measure Blood Serum Vitamin D
The amount of dietary Vitamin D we take in doesn’t correspond directly to the amount in our bloodstream. Doctors can order a lab test to check our levels. The reliability of that test is questionable, but we work with what we have and use the Food & Nutrition Board’s definitions of appropriate levels of Vitamin D. I note that the lab I use has slightly different definitions:
Before we get too dogmatic about those number being etched in stone, we need to recognize that the NIH fact sheet on Vitamin D tells us,
“Optimal serum concentrations of 25(OH)D for bone and general health have not been established because they are likely to vary by stage of life, by race and ethnicity, and with each physiological measure used. In addition, although 25(OH)D levels rise in response to increased vitamin D intake, the relationship is nonlinear. The amount of increase varies, for example, by baseline serum levels and duration of supplementation.”
Basically they’re saying that nobody knows for sure how much Vitamin D we truly need, but they’ve taken as good a guess as they can.
Then there’s the Endocrine Society, which says that people should get as much Vitamin D as it takes to keep their serum 25(OH)D levels above 75 nmol/L (30 ng/mL). That’s quite a bit higher than the Food & Nutrition Board’s recommendation that 50 is adequate.
Putting everyone’s guesses together, I take it to mean that ideal serum levels would be in the 75-96 range, and we need to figure out a safe way to get our Vitamin D to that level.
But we have to be careful. As with other fat-soluble vitamins, toxicity is a real possibility. Current theory tells us that 1,000 IU daily can raise the serum level by 10 ng/mL, so that much supplementation should theoretically be safe for people whose numbers are low. The Tolerable Upper Limit for adults is 4,000 IU, so 1,000 should be perfectly safe. Don’t take too much, though. Toxicity sounds not just unpleasant, but dangerous: nausea, vomiting, pain, dehydration, kidney stones, renal failure, heart problems, or death.
Note that those scary results of toxicity are thought to be from supplements. Getting Vitamin D from sunshine and food is considered safe.
Which foods contain Vitamin D?
Six ounces of salmon or swordfish contain 142% of the daily Vitamin D we need. An equal amount of halibut provides 50% of our day’s Vitamin D. A three-ounce can of tuna provides 9%.
Supposedly a 1-cup serving of crimini mushrooms has zero vitamin D, unless they’ve been treated with UV light, in which case they provide 122% of our daily Vitamin D. This is most peculiar. I’m not sure if it means we should be setting our mushrooms out in the sunshine before consuming them, or what the deal is, but if I had sunshine, I could set myself in it instead of my mushrooms.
Basically, unless you’re eating a ton of salmon every day or drinking milk, it’s nearly possible to get enough Vitamin D without taking supplements or going out in the sun.
How Much Sunshine Do We Need?
We don’t need as much sunlight as you might think. Up to one hour three times a week should be sufficient. Note that since Vitamin D is fat soluble, extra is stored (as opposed to water-soluble vitamins that are excreted if we get more than we need). It appears that we can spend time in the sun every-other-day, not daily.
How long we should spend in the sun depends both on how dark our skin is and on how intense the sunlight is. We just need to know the UV index – and I’ve discovered that my smart watch can provide that information. It’s also possible to check the weather forecast for the UV Index.
It’s not enough to look out the window to see if it’s sunny or not. UV index depends on other factors, including angle of the sun (ie time of day and season of the year). For instance, it’s a beautiful day here, but the sun is so low that despite the blue sky, the UV index is only 2.
Once I know the current UV index, GB Healthwatch has a handy table for looking up how much time is needed in the sun (while wearing shorts and a t-shirt). Unfortunately, they don’t document where the data came from. Nonetheless, it’s a starting point.
The average person needs 15 mcg of dietary Vitamin D, every day, or needs to spend up to an hour getting sunlight directly on the skin (directly, not through a window). The farther from the equator people live, the less likely they are to get adequate Vitamin D from the sun, so supplements might be needed. It’s also possible (but fairly expensive) to use a special UVB light or spend time in a tanning bed.
People with autoimmune diseases need to be especially vigilant in getting enough Vitamin D, both to help control inflammation, and to reduce the probabilities of complications such as cardiovascular disease and osteoporosis.
Wishing you well!
***** ****** ******
1 Food & Nutrition Board 2 National Academies of Sciences, Engineering, and Medicine
Have you noticed a little change on nutrition labels? Vitamin A used to be listed in IU’s (International Units), but is being changed to µg RAE (Retinol Activity Equivalents).
Apparently Vitamin A is more complex than initially thought. There’s so much more to it than eating carrots for good eyesight! Vitamin A is still fat soluble. It’s still important for vision. It is also critical for things like immune function and modulating inflammation – especially important if you have an autoimmune disease! What’s changed is what we know about how Vitamin A is metabolized.
animal sources contain pre-formedVitamin A (retinol & retinyl ester)
plant sources contain many different kinds of pro-vitamin A carotenoids, including but not limited to:
Our bodies bio-convert all of these nutrients so that we can use the active form of Vitamin A: retinal (and retinoic acid). It turns out that what researchers have learned about this process led to the change in units from IU to RAE. There’s a difference in how nutrients convert depending on their source. Confounding the researchers, when looking at IU’s, foods supposedly containing the same amount of Vitamin A can metabolize to vastly different amounts of usable retinal, which means that there isn’t a simple conversion factor to use to change all IU’s to RAE’s.1 Although we absorb about 70-90 percent of pre-formed vitamin A from animal sources, carotenoids are a different story. Plant-based Vitamin A is not metabolized nearly as well.
Consider two foods that many people consider disgusting: kale and liver. Both are good sources of Vitamin A, yet the nutrients look quite different between the old and new units of measure.
Kale (1 C = 67 g)
515 mcg RAE
Beef Liver (2 oz)
2,805 mcg RAE
IU’s make it look like kale has more Vitamin A, but when we look at how much retinal our bodies get to use from these foods, a serving of liver has more than five times as much.
Vitamin A & Autoimmunity For years, some people have suggested that autoimmune diseases are caused by nutrient deficiencies. Nutrition is especially important to people with autoimmune diseases. In the case of Vitamin A, we need sufficient amounts for our bodies to work correctly. Unfortunately, sometimes people think that they can just take a handful of vitamin pills instead of eating properly. It doesn’t work that way. We need to consume plenty of Vitamin A-rich foods if we’re to be as healthy as possible. Vitamin A is needed to do many things, including:
form natural killer cells
increase phagocytes to fight infection
increase anti-inflammatory cytokines
Why the Change in Units? The newer research about how bioconversion takes place indicates that some people are not getting nearly as much Vitamin A as they thought since not all IU’s are metabolized the same. Switching to RAE’s is better because it gives us a more accurate picture of the nutrients our bodies actually get to use.
One cup of kale provides 74% of the Recommended Daily Allowance for Vitamin A, while a two ounce serving of liver (because, honestly, who can stand to eat much more than that?) is well over the RDA and nearly to the tolerable upper limit (UL).
Yep, there’s an upper limit. Just as it is important to get enough Vitamin A, it is also important not to get too much. Toxicity can result from excessive intake. Vitamin A toxicity is more common when people are taking supplements, but can happen through dietary intake, too, generally from excessive amounts of liver. I find it slightly ironic that eating too much liver can be harmful to our livers.
Symptoms of toxicity are numerous and can include headaches, dizziness, nausea, joint pain, peeling skin, and in extreme cases coma, or even death. Severity depends on how much Vitamin A was ingested, and how fast. This theory says that symptoms would be more severe for a person who eats 5,000 mcg in one sitting, compared to a person who eats 1,100 mcg three times a day. Am I a terrible person for thinking that anyone who eats 4 ounces of liver shouldn’t be surprised that it makes them sick?
Curiously, excess plant-based Vitamin A is not toxic. The most-reported symptom is orange skin. I know someone whose baby loved carrots and ate so many that his face turned orange. Skin returns to its normal color when plant-sourced Vitamin A consumption is reduced.
So how much is enough, and how much is too much? According to the current research, dietary needs increase as we grow. Adult men tend to need more than adult women (probably because they tend to have larger bodies).
Do you ever wonder if people are just throwing darts at a dart board in making these recommendations? At least 700 µg RAE every day?! Are they out of their ever-lovin’ minds? People would have to quit their jobs and spend all their time menu planning & cooking in order to find a way to get that much Vitamin A on a regular basis!
How Do We Get Vitamin A? We can get some Vitamin A from plants. The best plant sources are bright orange or leafy green. Carrots and sweet potatoes (but not yams) have the most, followed by foods like kale, turnip greens, dandelion greens, radish leaves, and cantaloupe.
However, the Vitamin A from plants is in the carotenoid forms and isn’t metabolized very efficiently. We’re supposed to get animal sources, too. If you don’t consume dairy or eggs (which is now recommended by many), that means liver. Beef liver. Chicken liver. Liverwurst. Foie Gras. Braunschweiger. Cod liver oil. Liver is an excellent source of Vitamin A.
Don’t eat too much, because toxicity – mentioned previously – is a real thing. One source recommends limiting liver to six ounces per week, maximum.
From a Vitamin A standpoint, it’s not even necessary to eat that much liver. We could actually get our entire RDA of Vitamin A by eating half an ounce of beef liver daily. Or bring back the practice of taking a daily spoonful of cod liver oil.
But don’t get stuck in a rut. We’re actually supposed to get our nutrients from a variety of sources instead of eating the same thing every day. The USDA’s FoodData Central website has nutrient information on pork liver, veal liver, lamb liver, turkey liver, goose liver, duck liver, sea lion liver, walrus liver, and even moose liver — but not elk or deer, which are livers that I actually have access to. Go figure. Anyhow, what it comes down to is that unless you’re eating a ton of vegetables, you should probably eat liver, but a little bit goes a long way.
If you’re curious about the actual amounts of Vitamin A in veggies:
By comparison, other veggies don’t have nearly as much Vitamin A2. They do, however, contain other nutrients, so don’t neglect them:
So there you have it. Switching the units from International Units to Retinol Activity Equivalents lets us look at nutrient information and know how much Vitamin A our bodies will actually be able to use.
For meat and eggs (retinol sources), multiply IU by 0.3 to find mcg RAE
For fruits and vegetables with beta-carotene, multiply IU by 0.05 to find mcg RAE
For fruits and vegetables with alpha-carotene or beta-cryptoxanthin, multiply by 0.025 to find mcg RAE
2Nutrient info is from the US Department of Agriculture’s FoodData Central website, glycemic load information is from Self’s NutritionData database. Color groups shown are based on Dr. Terry Wahls‘ research, wherein she recommends eating 3C of leafy greens, 3C of brightly colored (try to hit more than one color), and 3C sulfur-rich foods daily. I have omitted nightshades and legumes because they are disallowed in the elimination portion of Wahls and AIP. Legumes didn’t make the re-intro cut for me (not a problem since I’m allergic to soy and probably peas and peanuts), and the only nightshade I really do okay with is tomatoes if they’re organic (but I react to standard store-bought tomatoes). More than you ever wanted to know, but that’s what determined what’s on the lists.