Is there bug spray in vitamin D? Sort of — but almost none
Claude AI, to a 10 year old child includes answer to an adult
Most vitamin D pills start out as sheep wool. Sheep get itchy bugs like lice and ticks, so farmers spray or dip them in bug-killer. Some of that bug-killer sticks to the greasy wax in their wool. That grease is called lanolin, and lanolin is what factories use to make vitamin D.
So far the rumor sounds true! But here's what happens next.
The wool goes through a long car wash
Before it becomes vitamin D, the lanolin gets boiled in strong soap, washed, filtered, split apart with chemicals, shined with UV light, heated, filtered again, and turned into crystals. Each step throws away more junk. By the end, there's basically nothing left of the original grease except the one molecule they wanted.
Now the fun part: the math
Let's pretend the cleaning did nothing at all. Zero. Say every bit of bug-killer stayed in.
A vitamin D pill has such a tiny speck of actual vitamin D that even in this pretend worst case, you'd swallow about 5 billionths of a gram of bug-killer. That's like one grain of salt split into a million pieces, and you take one piece.
Scientists say an adult could safely handle about 3,000 times more than that every single day. And remember — we pretended the cleaning did nothing, which is very far from true.
The funny twist
That pill you swallow? The vitamin D part is only about one ten-thousandth of what's inside. The rest is just oil — olive oil or sunflower oil.
So if you're worried about bug spray, the oil is where way more of it would come from. The sheep are the least of it. 🐑
The short version: it's a real thing that people checked, and it turned out to be too small to matter.Is there bug spray in vitamin D? Sort of — but almost none.
Most vitamin D pills start out as sheep wool. Sheep get itchy bugs like lice and ticks, so farmers spray or dip them in bug-killer. Some of that bug-killer sticks to the greasy wax in their wool. That grease is called lanolin, and lanolin is what factories use to make vitamin D.
So far the rumor sounds true! But here's what happens next.
The wool goes through a long car wash
Before it becomes vitamin D, the lanolin gets boiled in strong soap, washed, filtered, split apart with chemicals, shined with UV light, heated, filtered again, and turned into crystals. Each step throws away more junk. By the end, there's basically nothing left of the original grease except the one molecule they wanted.
Now the fun part: the math
Let's pretend the cleaning did nothing at all. Zero. Say every bit of bug-killer stayed in.
A vitamin D pill has such a tiny speck of actual vitamin D that even in this pretend worst case, you'd swallow about 5 billionths of a gram of bug-killer. That's like one grain of salt split into a million pieces, and you take one piece.
Scientists say an adult could safely handle about 3,000 times more than that every single day. And remember — we pretended the cleaning did nothing, which is very far from true.
The funny twist
That pill you swallow? The vitamin D part is only about one ten-thousandth of what's inside. The rest is just oil — olive oil or sunflower oil.
So if you're worried about bug spray, the oil is where way more of it would come from. The sheep are the least of it. 🐑
The short version: it's a real thing that people checked, and it turned out to be too small to matter.
The intake numbers
| Source | Daily amount (70 kg adult) | vs. vitamin D worst case |
|---|---|---|
| Vitamin D3, 5,000 IU — assuming zero purification | 5 ng | 1× |
| Swallowed house dust (~30 mg/day at median permethrin) | ~32 ng | ~6× |
| Same, a toddler (~100 mg dust/day, hand-to-mouth) | ~106 ng | ~21× |
| Diet alone, no home spraying | 2,500–5,000 ng | ~500–1,000× |
| Someone using permethrin yard/clothing products | 100,000+ ng | ~20,000×+ |
Diet is the floor, not the ceiling: FDA market-basket surveys put average permethrin intake at 36–71 ng/kg/day. A duplicate-diet study of North Carolina adults found maximum single-food-item intakes ranging from 38 ng/kg/day for deltamethrin up to 939 ng/kg/day for permethrin. California EPA's permethrin risk document estimated general-public absorbed doses of 1.6–3.0 µg/kg/day averaged over a year for home and recreational product use.
Your vitamin D pill might have a speck of bug spray in it too small to find. Meanwhile, if anyone in your house has ever sprayed for ants, spiders or fleas, that spray is still on your floor and in your carpet — and a bit of it is in you right now. Scientists can find it in about 8 out of every 10 Americans. The pill isn't where the bug spray comes from. The bug spray is where the bug spray comes from.
Related in VitaminDWiki
- Pesticides 8 X less likely to result in female infertility if take vitamin D
Vitamin D helps your body fight pesticides - 20+ chronic stressors result in poor health (most are fought by Vitamin D)
Vitamin D fights many stressors, not just pesticides