Liposomal Vitamin C

Liposomal vitamin C is ascorbate encapsulated in phospholipid vesicles, sold to overcome the absorption ceiling that limits ordinary oral vitamin C.

The ceiling is real

Vitamin C absorption is saturable. It is taken up by the SVCT1 transporter, which is downregulated as intake rises. The measured consequence:

200 mg oral — nearly 100% absorbed
1,000 mg — roughly 50%
1,250 mg — plasma plateaus near 80 μmol/L and further oral dose barely moves it

Intravenous ascorbate bypasses the transporter entirely and reaches plasma concentrations 30–70× higher than any oral dose can. That difference is not marketing — it is the reason the high-dose vitamin C oncology literature is an intravenous literature, and why oral trials of the same idea failed.

Liposomal encapsulation is an attempt to get part of the way there orally, by having the vesicle absorbed by a route that is not SVCT1.

Does it work

Partially, and less than claimed. Independent pharmacokinetic comparisons find liposomal formulations produce higher plasma levels than the same oral dose of plain ascorbate — but well short of intravenous, and short of what the marketing implies. Product quality varies enormously: many "liposomal" products are simple lecithin mixtures with no verified vesicle formation, and few manufacturers publish particle characterisation.

The most reliable and cheapest way to raise absorbed vitamin C from an oral dose remains splitting it — 250 mg four times a day beats 1,000 mg once, and beats most liposomal products at a fraction of the price.

Role in the stack

In The Amplification Framework vitamin C occupies the degradation inhibitor row: it reduces the BH3 radical back to BH4, the cofactor that L-methylfolate regenerates. It is also the cofactor for prolyl and lysyl hydroxylase in collagen synthesis, which connects it to silicon, and it reduces dietary iron to the absorbable ferrous form — which is useful with iron and unhelpful in iron overload.

Cautions

Osmotic diarrhoea is the dose-limiting effect of plain ascorbate; liposomal formulations reduce it, which removes the body's own signal that intake is high.
Kidney stones — ascorbate is metabolised to oxalate. Relevant in stone-formers and in renal impairment, and more so at gram doses.
G6PD deficiency — haemolysis reported at very high (intravenous) doses.
Iron overload conditions — vitamin C increases iron absorption and mobilises stored iron.
Interferes with glucometer readings at high doses.