This secret food can produce vitamin D even after you buy it...
Vitamin D for overall health, mushroom-filled stir-fried turnip greens, and how I determine recipe serving size
👉This week, we’re talking about: vitamin D as a true health multitasker; mushrooms as a nutritionally unique vegetable; how to make vitamin D-enhanced mushrooms at home (it’s easy!); how I determine recipe serving sizes (and it’s okay not to follow them!); and I’m sharing my recipe for Stir-Fried Turnip Greens with Mushrooms and Almonds.1
Key Takeaways
✅Vitamin D isn’t a “true” vitamin, it’s a steroid hormone that controls over 200 genes!
✅Maitake mushrooms are the 29th most nutrient-dense food, and one of our best food sources of vitamin D!
✅Let’s get nerdy about how I determine recipe serving sizes, even though that’s not the real question…
✅For paid subscribers, your downloads this week are: Top 10 Vitamin D Foods Fridge List and Stir-Fried Turnip Greens with Mushrooms and Almonds
Vitamin D for… Well, Everything!
🧬Rather than being a “true” vitamin, vitamin D is a group of fat-soluble steroid hormones that can be either obtained from the diet or synthesized from sun exposure. (For this reason, vitamin D is sometimes nicknamed “the sunshine vitamin”!)
Vitamin D has control of over 200 genes (and the proteins they regulate)! As a result, vitamin D is heavily involved in many biological processes, including immune function, cell differentiation, gut barrier function, nutrient absorption (particularly of calcium, magnesium, and phosphorus), bone formation, endocrine health, cardiometabolic health, and neurological health. As a result of these diverse functions, getting enough vitamin D is important for protecting against chronic disease (including diabetes, cancer, and degenerative neurological conditions), maintaining good gut health, and keeping a healthy immune system (including protecting against both infectious disease and autoimmunity). I mean, it’s probably easier to ask what vitamin D doesn’t do!
Because vitamin D can come from both food and our body’s own synthesis, it’s been difficult to establish a guidelines for the amount of vitamin D each individual needs. The current recommended dietary allowance (RDA) is 600 IU per day for adults (800 IU per day after the age of 70), with a tolerable upper limit set at 4000 IU daily (meaning beyond this level, the risk of harm begins to increase). However, for those with vitamin D deficiency or insufficiency, many medical professionals are shifting towards individualized doses of vitamin D supplements to sustain optimal serum levels, rather than a standard supplementation dose. This involves testing 25-hydroxyvitamin D level every 3 to 6 months, and adjusting the dose of vitamin D supplementation accordingly.
The food sources of vitamin D are slim and are all primarily fish. So if you are looking to increase your vitamin D with food, nearly any kind of fish will do: salmon, carp, eel, mackerel, swordfish, tuna, bass, halibut, etc. One of the only non-animal sources of vitamin D is mushrooms, especially maitake mushrooms. However the caveat here is that the mushrooms must be grown under UV exposure to produce naturally occurring vitamin D (mostly in the form of vitamin D2, which has been shown to bring up our vitamin D levels comparably with vitamin D3). Otherwise, you can use the simple trick in the Helpful Tip of the Week Section below to increase the vitamin D content of any mushrooms you buy at the store!
Want to know the top 25 best food sources of vitamin D? Learn them here.
Get 108% DV Vitamin D with Maitake Mushrooms
🍄🟫Although they’re categorized as vegetables, mushrooms are nutritionally unique. That’s because, unlike all other vegetables which are plants, mushrooms belong to an entirely separate biological kingdom, called Fungi. Along with having high concentrations of vitamins and minerals per calorie, mushrooms are among the most concentrated food sources of a variety of nutrients, including: ergothioneine (aka “the longevity vitamin”, several special types of fiber (glucans, chitin, and chitosan), triterpenes, catechins, gallic acid, gentisic acid, myrecetin. Mushrooms are also one of the only non-animal food sources of vitamin D, with maitake being the highest.
In addition to 108% DV vitamin D, a serving (1 cup, measured raw) of maitake mushrooms will give you 65% DV biotin, 32% DV vitamin B3, 22% DV copper, 14% DV vitamin B2, 2.1 grams of fiber, and 12.2 mg of ergothioneine, all for a measly 24 calories, which is why maitake mushrooms have such a high Nutrivore Score of 3551!
Maitake mushrooms are the 29th most nutrient-dense food! Learn the Top 500 Nutrivore Foods here.
Stir-Fried Turnip Greens with Mushrooms and Almonds
🥗 Turnip greens are a cruciferous vegetable in the same family as cabbage, kale and broccoli. Not only are they packed with nutrients, but they are a hearty unique flavor that stand up to other strong seasonings such as soy sauce or your favorite spicy condiment, and they pair amazingly with the soft, meaty texture of sauteed mushrooms! If you can’t find them at the grocery store or your local farmer’s market (they’re also very easy to grow from seed if you’re looking for a project), you can use collard greens, kale, or radish tops in this recipe instead.
Add this recipe to your meal plan this week with Real Plans, the official Nutrivore meal planning app!
Nutrivore Mindset Corner
🧠This year, I started a new style of video for social media where I do a nutritional analysis, including calculating the Nutrivore Score, of trending recipes (watch on YouTube, TikTok, Instagram, or Facebook). It’s a fun way to teach about nutrients while highlighting the nutritional value of delicious, comforting recipes that many people might assume aren’t healthy because of wrong messages learned from diet culture. These videos have been very popular, which is awesome (and a special hello to everyone who subscribed to my Substack because you’ve been enjoying these videos!), and I’ve noticed an interesting theme in the comments that I want to discuss today, people asking: How is serving size is determined?
Of course, there are standards set by the USDA and based in scientific research for defining a serving of vegetables, fruits, grains, seafood, meat, cheese, nuts, etc.; but that’s not what people are asking. (If that was what you were wondering though, don’t worry, I list serving sizes for all the different food groups here.) Instead, this question pertains to the whole recipe that I’m talking about, and seems to be stemming from a diet culture-driven fear of “eating too much”.
So, when I share my nutritional analysis of a recipe, how do I determine portion size?
Most of the time, I’m not the one making the determination. Instead, the recipe developer has indicated how many servings their recipe makes, and I am simply doing the nutrient calculations based on their portion recommendations. Sometimes the recipe developer shares how many calories (or grams of protein or fiber) each serving has, and I have to figure out from that how many servings the recipe makes from that, but I’m still just matching their recommendations.
Okay, we’re getting into the weeds here, but in the instances where the recipe developer has not specified recipe yield, I have to figure it out. Here’s my process: I look at the main ingredients in the recipe, what type of recipe it is (main course, veggie side, starchy side, breakfast, snack, etc.) and guestimate based on standard serving sizes of the main ingredients. For example, if the recipe uses a pound of chicken, my first guess will be that it serves four, since a serving of meat is 4 ounces. Then I look at the nutrition (especially calories and protein grams) and see if that makes sense, and adjust up or down. For example, if I assumed 4 servings because the recipe uses a pound of chicken, but then that comes out to 900 calories and 65 grams of protein, I’ll redo the analysis with the recipe serving 6 instead. I generally aim for 600 to 750-ish calories for a main course, 200 to 400-ish calories for a side dish, 300 to 500-ish calories for breakfast or dessert, and around 300-ish calories for a snack.
And that brings me to the real answer to this question! I want to emphasize that just because the recipe developer or I have defined a portion in a specific way, that doesn’t mean that you have to eat that much food, nor do you you have to limit yourself to that much food. You’re allowed to eat more or less than a portion size of a recipe! And you’re allowed to eat enough to feel full!
Learn everything you need to know about the Nutrivore philosophy in my book, Nutrivore: Eat Any Food, Get Every Nutrient, and Transform Your Health!
Helpful Tip of the Week
💡In general, wild-harvested mushrooms contain high levels of vitamin D due to being exposed to sunlight out in nature, while commercially grown mushrooms contain negligible amounts. But did you know that mushrooms can actually generate vitamin D in response to UV exposure even after they’ve been harvested?
A variety of studies show that exposing fresh-picked (raw) mushrooms, such as white button or oyster, to sunlight for 15 to 30 minutes increases their vitamin D content impressively! Sliced mushrooms generate even higher vitamin D quantities, due to increased surface area allowing for greater exposure of vitamin D precursors to UV light. It’s typical in these studies for vitamin D to increase by 20 times or more, and typically yielding 100% to 200% DV per serving of mushrooms! Sun-dried mushrooms also generate vitamin D during their dehydrating process, regardless of how they were grown.
So, yes, this means you can make your own “vitamin D enhanced” mushrooms at home! A simple way to do this is to slice them, lay them out on a baking sheet, and put them outside in the sun for half an hour or so. Then cook them however you were planning (vitamin D is quite stable in the cooking process), or enjoy them raw!
This Week’s Downloads
📥For paid subscribers, your downloads this week are:
Top 10 Vitamin D Foods Fridge List - This 1-pager PDF guide lists the top 10 common whole food sources of vitamin D, how much vitamin D you get per serving (and how much a serving is!), while highlighting a few other valuable nutrients each food provides.
Stir-Fried Turnip Greens with Mushrooms and Almonds Recipe - A beautifully-designed PDF version of this week’s recipe that you can save or print out, to build your own personalized Nutrivore Cookbook week by week.
You can find buttons to download at the bottom of this Substack. Thank you so much for supporting my work and Nutrivore!
Sincerely,
Dr. Sarah Ballantyne, PhD
Founder of Nutrivore
Medical Disclaimer: The information provided in this Substack is for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified healthcare provider with any questions you may have regarding a medical condition or dietary changes.
FTC Disclosure: Some links in this Substack may be affiliate links, meaning I may earn a small commission if you purchase through them at no additional cost to you. I only recommend products I genuinely believe in. Thank you for supporting my work!
For Paid Subscribers
