Vitamin D · the body in the room
F.11
V.00

Form follows function · the vitamin D beat

The standard
was set on
eight bodies.

Eight adult male volunteers. 1974. Letterman Army Institute. Race unspecified. The reference range every body in the country is measured against came from this sample.

V.1
V.1
V1.01

Part I · The threshold

The threshold reads deficient
at every setting below.

Skin type. Latitude. Indoor hours. Three inputs the standard did not stratify against. Move them.

Fitzpatrick skin type IV
I
II
III
IV
V
VI
Latitude (degrees from equator) 42°
Indoor hours per day 14

What the body actually synthesizes

The vertical mark is the US Endocrine Society "sufficient" threshold (30 ng/mL). The standard is set against a body that synthesizes vitamin D at Type I rates under Type I conditions.

The label says

V.2
V.2
V2.01

Part II · The body across a lifetime

Sun.
Food.
Capsules.
The body adds them anyway.

Each source contributes. Each source the standard measures separately. The body has been integrating them for decades.

Years tracked 25

25(OH)D level (ng/mL) across the years

The body the standard imagined (Type I, low latitude, outdoors) The body in this room

V.3
V.3
V3.01

Part III · The cofactor cascade

D3 alone is accounting fiction.
The cofactors complete the conversion.

Magnesium converts D3 to its active form in the liver. Zinc lets the receptor express. Vitamin K2 directs the calcium. Without them, the capsule number rises and nothing arrives at the cell.

Toggle the cofactors that are present

Conversion to active 1,25(OH)2D
20%

Without cofactors, the liver and kidney conversion runs at a fraction of capacity. 20% of the D3 in the bloodstream becomes the hormone that reaches the receptor.

Functional amount needed to match
5.0×

To deliver the cellular effect of one functional unit, the deficient body must consume five times the capsule label.

V.4
V.4
V4.01

Part IV · The cohort

Tracked across decades.
Replicated across populations.

The bodies the standard called deficient have been telling a different story the whole time.

Black Americans. Maasai. Adventist Health Study. Hollis–Wagner pregnancy cohort. Coimbra autoimmune protocol. The integral has been measuring itself the whole time.

V.5
V.5
V5.01

The three tiers

Solid ground.
Real direction.
A model.

solid ground

Vitamin D is a secosteroid hormone regulating over a thousand genes. Black Americans synthesize at one-sixth the rate of white Americans under identical sun. The Powe 2013 binding-protein paradox is documented. Aloia's bone-density data is documented. These are not in dispute.

real direction

The cofactor cascade — magnesium, zinc, K2, A, boron — is established biochemistry. The autoimmune optimum range above 40 ng/mL is supported by Hollis–Wagner pregnancy data and the Coimbra protocol case literature. The exact amount for one body is still being worked out.

a model

The synthesis-rate curves, the conversion percentages, the cohort multipliers — these illustrate the architecture. They are not a reading of any one body. The real reading comes from a 25(OH)D panel with bioavailable D, magnesium, parathyroid hormone, and intact PTH.

The open question

Where does your body sit,
and what does it need.