Cabbage.

Cabbage glucobrassicin yields indole-3-carbinol on chopping and chewing, and stomach acid condenses that into diindolylmethane. The supplement is the downstream product of the vegetable's own chemistry.

Cabbage carries glucoraphanin, which plant myrosinase converts to sulforaphane once the tissue is damaged. The isolated compound is the activated form of what cabbage supplies as a precursor.

Sinigrin is the dominant glucosinolate in cabbage and myrosinase converts it to allyl isothiocyanate. The two are precursor and product in the same enzymatic step.

Thiocyanate released from brassica glucosinolates competes with iodide at the sodium-iodide symporter, so a large raw cabbage intake alongside a low iodide intake lowers thyroid iodide uptake.

Cabbage is a concentrated source of phylloquinone, the same vitamin K1 that drives hepatic synthesis of clotting factors. A cabbage-rich intake adds to a vitamin K1 dose rather than acting separately from it.

Cooking destroys cabbage's own myrosinase, leaving glucosinolates largely unconverted. An extract that retains active myrosinase restores the conversion step and raises isothiocyanate yield from the same glucosinolate load.

Lactobacillus plantarum is the dominant organism in the later stages of spontaneous cabbage fermentation, and it is what converts cabbage sugars into lactic acid in sauerkraut and kimchi. The same fermentation alters the glucosinolate breakdown products present in the finished food. A fermented cabbage preparation and this organism are therefore the same system rather than two additive ingredients.

Fermented cabbage carries live lactic acid bacteria and their metabolites, so it overlaps with what a probiotic preparation supplies. A registered study compares fermented with unfermented red cabbage on immune and inflammatory markers and on gut microbiota composition. Microbiota composition is a marker, not a clinical outcome.

Raw cabbage is a meaningful food source of ascorbic acid, and that content falls with prolonged heating and with industrial dehydration. A vitamin C preparation and cabbage supply the same molecule by different routes. Processing method is what decides how much survives in a dried cabbage powder.

The ascorbate in cabbage reduces ferric iron to the ferrous form at the intestinal brush border, which raises the fraction of non-heme iron absorbed from the same meal. This is settled nutrition chemistry and holds for any ascorbate-containing vegetable. It applies to iron eaten at the same sitting, not to iron taken hours apart.

Selenium is built into glutathione peroxidases and thioredoxin reductases, and cabbage isothiocyanates are described as inducing NRF2-directed phase II enzymes in preclinical work. The two feed the same cellular antioxidant machinery from different ends. The induction side comes from laboratory models, not human outcome data.

Cabbage carries kaempferol and quercetin glycosides alongside its glucosinolates, and red cabbage adds anthocyanins. These flavonoids participate in the same electron-transfer cycles as ascorbate in redox assays. Assay activity is a laboratory measurement rather than a health endpoint.

Cabbage contributes insoluble and soluble fibre that colonic bacteria ferment, and inulin is a defined fermentable fructan. Both raise the substrate load reaching the colon. That also means both can add to gas production when intake rises quickly.

Fermentation of cabbage fibre by colonic bacteria produces short-chain fatty acids including butyrate, which is the preferred fuel of colonocytes. A butyrate preparation delivers the same molecule directly rather than through fermentation. The relationship is a shared endpoint of one established pathway.

Brassica vegetables carry phytate and fibre that bind divalent minerals in the gut lumen and reduce the fraction absorbed. Zinc is one of the minerals affected. The effect is modest for cabbage compared with whole grains and legumes, and it applies to minerals eaten in the same meal.

Cabbage is low in oxalate compared with most leafy greens, so the calcium it carries is relatively available; its fibre still binds some mineral load in the same meal. Cabbage is not a major calcium source in its own right. The practical point is meal timing, not avoidance.

Isothiocyanates released from cabbage glucosinolates are conjugated with glutathione by glutathione S-transferases and excreted as mercapturic acids. Glutathione status is therefore part of how these compounds are handled and cleared. This is settled xenobiotic metabolism, not a supplementation finding.

Cabbage brings raffinose-family oligosaccharides that human enzymes cannot break down, which is why it ferments in the colon and produces gas. Alpha-galactosidase containing enzyme products are used against exactly that substrate. This is a tolerability pairing rather than a nutritional one.