Okay so B12 vs iron has been low-key ruining my life for like the last two years and I’m only now sort of getting a grip on it. I went fully plant-based in late 2023 here in the States—thought I was gonna glow up, you know? Eat tons of spinach, lentils, kale smoothies that taste like lawn clippings. Fast forward to summer 2024 and I’m dragging myself out of bed at 2 p.m. feeling like someone replaced my blood with lukewarm oatmeal.
First I blamed iron. Classic vegan rookie move. I was eating spinach salads every day, throwing handfuls of pumpkin seeds on everything, even bought this cast-iron skillet because TikTok told me it would “naturally fortify” my food. My ferritin was still trash. Like 18 ng/mL trash. Doctor looked at me like “ma’am you’re pale as the inside of a potato.”
Then someone in a Reddit thread screamed B12 at me. I started B12 supplements (cyanocobalamin 1000 mcg sublingual because I’m extra) and within like three weeks the brain fog lifted so hard I almost cried in the grocery store parking lot. But guess what? My iron still sucked. So now I’m sitting here in January 2026 in my freezing apartment in [insert your city if you want, otherwise just imagine Midwest gloom], sipping black coffee that tastes like regret, trying to figure out B12 vs iron and why they both hate me simultaneously.
Why B12 vs Iron Feels Like They’re Fighting in My Body
Here’s the chaotic truth nobody tells you when you go plant-based:
- B12 is basically only in animal products (or fortified stuff and supplements). Plants don’t make it. Algae and tempeh claims are mostly wishful thinking or super inconsistent.
- Iron from plants (non-heme) is way less bioavailable than heme iron from meat. Plus coffee, tea, calcium, and even high-fiber foods block absorption like petty exes.
So you can fix your B12 pretty reliably with a supplement or fortified nutritional yeast, but iron? That’s a whole personality test.
I once took an iron supplement on an empty stomach with orange juice (vitamin C helps!) and spent the next four hours feeling like I swallowed a hot nail. True story. Now I take it with food and a little vitamin C powder and it’s… tolerable?
My Current Plant-Based B12 vs Iron Game Plan (Flawed But Working-ish)
This is what I do right now in 2026—take it or leave it, I’m not a doctor and I still feel tired sometimes:
- B12: 1000–2000 mcg cyanocobalamin every other day or daily 250 mcg methylcobalamin if my wallet is feeling fancy. I use Deva Vegan B12 because it’s cheap and actually dissolves under my tongue instead of tasting like battery acid.
- Iron: 18–29 mg ferrous bisglycinate (gentler on stomach) 2–3× per week, always with vitamin C. I pair it with this one from Thorne because the constipation is way less demonic.
- Food sources I actually eat: lentils + bell peppers (vitamin C), blackstrap molasses in oatmeal (tastes like regret but iron is decent), pumpkin seeds by the handful while watching Netflix.
- I avoid calcium supplements or fortified plant milk within 2 hours of iron—learned that the hard way after a smoothie + iron pill disaster.
Get bloodwork every 6 months. Seriously. I ignored it for a year and paid for it with hair falling out in the shower. Not cute.
Quick Reality Check: You Probably Need Both
If you’re plant-based long-term in the United States right now:
- Almost everyone needs supplemental B12. No exceptions unless you’re eating fortified foods religiously.
- Iron is trickier. Some people absorb plant iron fine; others (hi, me) need supplements forever.
- Women, athletes, heavy bleeders—y’all are at extra risk for iron issues.
- B12 deficiency can mimic iron deficiency (fatigue, weakness, brain fog) so test BOTH ferritin + B12 + maybe MMA/homocysteine if you’re fancy.
More reading if you’re nerdy like me:
- NIH Office of Dietary Supplements – Vitamin B12
- NIH Office of Dietary Supplements – Iron
- Academy of Nutrition and Dietetics position on vegetarian/vegan diets
Wrapping This Mess Up
Look, B12 vs iron isn’t sexy. It’s not “superfood this” or “miracle that.” It’s me sitting here at my tiny kitchen table surrounded by empty supplement bottles, half-dead houseplants, and a cold bowl of lentil soup wondering if I’ll ever feel normal again.
But I do feel better than I did in 2024. So if you’re plant-based and tired all the damn time—get your levels checked, supplement smart, pair iron with vitamin C, and don’t listen to the crunchy people who say spirulina has enough B12. It doesn’t.
Drop your own horror stories or wins in the comments. Misery loves company and honestly I need to know I’m not the only one who cried over a ferritin number.
Love y’all. Take your B12. Eat some lentils. We got this (probably).
