I’ll start with vitamins, because that’s what the product is marketed based on. Vitamin A immediately stands out to me. There are two kinds of vitamins, water soluble and fat soluble. Vitamin B is a great example of a water soluble vitamin. If you’ve ever had a vitamin B supplement, then gone for a pee later, you might have noticed it being -really- yellow. That’s excess vitamin B. Because it’s water soluble, your body will just excrete any excess that you don’t need; there’s very little danger of it building up in your system.

Vitamins A, D, E and K, on the other hand, are fat-soluble. This means they get stored in your body and used as needed, so it is technically possible to overdose on these over a long enough timeline. Vitamin D and E poisoning from diet is pretty rare, but Vitamin A is kinda famous in nutrition circles. Every first year nutrition student learns about Vitamin A toxicity killing most of Mawson’s antarctic expedition. Those were pretty extreme circumstances, but so is living on nothing but fortified cereal.

1383.6ug is nearly twice the RDI. According to Horowitz, daily vitamin A over 50,000IU (1ug vitamin A = 3.33IU) can cause poisoning over time, with acute toxicity kicking in at a single dose of 1,000,000IU or more. Our 1383ug maths out to 4610IU. Probably won’t feel great, but it’s a fair way short of fatal.

Let’s do the other vitamins while we’re on the subject. The essential vitamins are A, C, D, E, K, and the B group. A, we’ve covered. C is water soluble, so we’re fine to blow right past the RDI there. For vitamin D, the maximum suggested is 4,000IU / day, where 1IU = 40ug. At 9.1 serves, we’re getting 1.63ug, or 65.2IU. Nowhere near the danger zone, but with an RDI of 5ug, we’re at risk of deficiency. Dietary vitamin D deficiency is unlikely to straight up kill a person, especially if if they’re getting enough sunlight, but is a risk factor for osteoporosis and other issues later down the line.

Vitamin E toxicity kicks in at about 1000mg / day, but can take years to develop. Our 9.1 serves gives 65mg. Fairly safe on that front.

Vitamin K isn’t mentioned in the NIP at all, and I get the feeling it isn’t well understood (the NRV section on it contains a lot of unknowns, and doesn’t list an RDI – 120ug / day is the US recommendation). However, there probably isn’t any significant amount in our cereal given the main sources are green leafy veg, some cheeses and plant oils. Vitamin K is important for blood clotting, with adverse effects starting at <10ug / day. Although humans can’t synthesise it ourselves, apparently our gut flora can, at least to some degree. I don’t think enough is known about this to really say how long it’d take to kill a person, but if our test subject starts bleeding profusely, we’ll know why.

B group vitamins we’re fine for. Like I said above, we can go way beyond RDI and the excess will be excreted. Even being short on B5 and B7 per serve works out okay; with the amount we’re eating, we’re getting 5.8mg / day B5, and 62.8mg / day B7. Above RDI in both cases, and we’ll just pee the surplus out.

So yeah, vitamin-wise, it’s plausible. Can’t say I’d recommend it though.

Let’s move on to minerals. Most of these we don’t need a ton of, apart from calcium, but they are important for catalysing certain chemical reactions in our bodies, like how iron helps bind oxygen to red blood cells. We’ll skip chloride, sulphur, potassium and sodium for the moment, those are special cases that need a bit more explanation.

We’re under for chromium, copper, manganese and zinc, and well over RDI for calcium, iodine, iron and seleneium. Just over for molybdenum and phosphorus.

Mineral deficiencies and excesses can be just as dangerous as vitamins. Iodine is necessary for thyroid function, but excess can cause bloody diarrhea and siezures, for example. Thankfully we’re well below the danger threshold of 1mg/day. Excess calcium isn’t considered particularly risky; there’s some evidence suggesting it’s a risk factor for brain lesions and vascular disease, which may start to become a problem at around 2000mg/day (we’re getting just over that), but probably depends on other pre-existing risk factors and there’s a lot of unanswered questions. The current advice is to stick to about half what we’re getting in this exercise, but I can’t really say when or if our test subject would die from a fatal brain lesion.

Selenium overdose can be straight up lethal (~3mg/kg bodyweight in rats), but we’re a fair way below that at 0.5mg / day total. However, this level has been flagged as probably being the maximum allowable intake in humans. Side effects of excess selenium include bad breath and teeth, arthritis, skin and nail issues, and liver dysfunction. Probably not immediately fatal, but pretty dicey and could get very unpleasant.

Despite getting over 900% RDI of iron, we’re not in much danger of excess there either; iron poisoning usually doesn’t happen just from diet; it’d take a huge dose all at once to be fatal. Especially since most of the iron here is non-heme (supplements and fortifications are usually made from plant sources because they’re cheaper), which doesn’t absorb anywhere near as well. Although the upper limit is 45mg from all sources, it’s unlikely to be deadly at least in the short term as the liver regulates iron uptake; excess will get excreted, for the most part. Worth noting that this system can get overwhelmed in the long term (similar to how excess sugar causes diabetes), and in the short term it can cause some pretty nasty digestive effects; constipation, abdominal pain, nausea, and in extreme cases stomach ulcers.

Molybdenum isn’t much concern, especially since we’re not much past RDI and excess from diet is usually excreted. Same with phosphorus; the upper safe limit is around 4000mg / day; below that it isn’t usually a concern in people with healthy kidneys.

Chromium is an interesting one, we don’t actually have much data on it. None of the studies into chromium requirements are considered good enough to base an RDI on, so the adequate intake (AI) is based on the amount that healthy people tend to get. Near as we can figure it does something with glucose and insulin. Deficiency is really rare in humans; you might end up with some blood sugar issues over a long enough timeline by not getting enough, but really this one is a big fat shrug.

Copper and manganese are similar. We don’t know enough about them to set an RDI. Copper deficiency is likewise pretty rare, but can cause vascular, skeletal and nervous system problems, as well as anaemia, believe it or not. Manganese deficiency is rare enough that we don’t actually know what it does, beyond skin and cholesterol issues. Another shrug here. There just isn’t enough data.

And finally Zinc. This one we do know about. Deficiency here can impair growth, pregnancy outcomes, (neither of which are particularly relevant in our case), but also importantly immune function. More sever deficiency can cause alopecia, diarrhoea, low appetite and lesions. Interestingly, high iron and calcium intake can decrease zinc absorption. Given the excessive amount of iron and calcium we’re getting here, this would be one to watch.