Discussion Why does the PPH advise 35g for anyone above 100 kg if the upper lethal dose is estimated to be 250 mg/kg?

[Eudaimonic]

And 25g for anyone under 100 kg? For a 99 kg person the upper lethal dose would be ~25g, and since most people vomit, wouldn't they need to take more?

This doesn't make sense to me. The dose should scale more or less linearly with body weight, no?

"For nitrite, the estimated oral lethal dose for humans ranges from 1.6 to 9.5 g (Gowans, 1990; Mirvish, 1991) and from 33 to 250 mg/kg" - https://www.canada.ca/en/health-can...eline-technical-document-nitrate-nitrite.html

 

[onmywaytothebusstop]

And 25g for anyone under 100 kg? For a 99 kg person the upper lethal dose would be ~25g (and most people vomit), so wouldn't they need to take more?

This doesn't make sense to me. The dose should scale more or less linearly with body weight, no?

"For nitrite, the estimated oral lethal dose for humans ranges from 1.6 to 9.5 g (Gowans, 1990; Mirvish, 1991) and from 33 to 250 mg/kg" - https://www.canada.ca/en/health-can...eline-technical-document-nitrate-nitrite.html

The recommended dose used to be a lot lower than 25 and has been adjusted through the years.

You can catch the bus and ride at 25km/h to your destination and hope you have enough food and drinks for the ride or you can catch the special bus driving at 100km/h making sure you reach your destination.

Some people need less food and water for the ride and will be fine on the slow bus.

Also, it's not only the weight that counts. With weight comes size, more circulating blood i suppose, different metabolism etc...

 

[Eudaimonic]

The recommended dose used to be a lot lower than 25 and has been adjusted through the years.

You can catch the bus and ride at 25km/h to your destination and hope you have enough food and drinks for the ride or you can catch the special bus driving at 100km/h making sure you reach your destination.

Some people need less food and water for the ride and will be fine on the slow bus.

Also, it's not only the weight that counts. With weight comes size, more circulating blood i suppose, different metabolism etc...

Yes, the weight is also a proxy for those things. I don't understand why they advise just 35g for anyone over 100 kg, though. What evidence is there that the dose-weight relationship is nonlinear?

 

[onmywaytothebusstop]

Yes, the weight is also a proxy for those things. I don't understand why they advise just 35 kg for anyone over 100 kg, though.

I mean i'm 68kg and take 25g just like someone who weighs 40% more than me. They adjusted their plan based on experience reports and testimonies.

I believe that at some point it was just recommended to take 10g and people still died. Some people with very good health probably survived and suffered so they upped the dose.

The 35g is probably a failsafe to make sure people wouldn't suffer too much.

 

[Eudaimonic]

I mean i'm 68kg and take 25g just like someone who weighs 40% more than me. They adjusted their plan based on experience reports and testimonies.

I believe that at some point it was just recommended to take 10g and people still died. Some people with very good health probably survived and suffered so they upped the dose.

The 35g is probably a failsafe to make sure people wouldn't suffer too much.

Okay, but what I don't understand is what makes them believe that the dose-weight relationship is nonlinear such that a 150 kg person needs the same dose (35g) as a 100 kg person. What evidence is there for this being the case? They never provide any rationale.

 

[onmywaytothebusstop]

Okay, but what I don't understand is what makes them believe that the dose-weight relationship is nonlinear such that a 150 kg person needs the same dose (35g) as a 100 kg person. What evidence is there for this being the case? They never provide any rationale.

At a certain point, your blood will be saturated with methemoglobine. There's only so much blood a person can have and the amount of blood someone has in their body isn't linear with their weight.

 

[Eudaimonic]

At a certain point, your blood will be saturated with methemoglobine. There's only so much blood a person can have and the amount of blood someone has in their body isn't linear with their weight.

What is odd to me is that the range cited is only 0.7-9.5g (and this seems to be with intervention in most cases), which does track with dose-weight relationship being nonlinear and actual lethal dose in humans being lower than 250 mg/kg (which if I understand correctly is likely based on the LD50 used in animal studies, hence the use of per kg)

Also, the LD50 for an adult human is estimated to be 2.6g.

Anyway, thank you for your replies. I guess this was a dumb question lol

I feel really stupid now, but I'm going to leave this post up for anyone who was also confused.

 

[onmywaytothebusstop]

What is odd to me is that the range cited is only 0.7-9.5g (and this seems to be with intervention in most cases), which does track with dose-weight relationship being nonlinear and actual lethal dose in humans being lower than 250 mg/kg (which if I understand correctly is likely based on the LD50 used in animal studies, hence the use of per kg)

Also, the LD50 for an adult human is estimated to be 2.6g.

Anyway, thank you for your replies. I guess this was a dumb question lol

I feel really stupid now, but I'm going to leave this post up for anyone who was also confused.

I don't think you're stupid or that you should feel stupid for that.
You're asking questions that make sense to ask.