Vitamin D status (low-D genetic burden)

Three common genes, GC (the protein that carries vitamin D in blood), CYP2R1 (which activates it) and DHCR7/NADSYN1 (part of how skin makes it), each nudge your blood vitamin D up or down. Combining all three into one low-vitamin-D tendency reads the genetic leaning better than any single one. Sun exposure and diet still dominate; this is a mild nudge.

Possible results

Tends toward lower vitamin D. You carry a higher load of the common variants linked to lower blood vitamin D across all three of these genes, so you may run low more easily, especially in winter, with darker skin, or with little sun. This is a mild genetic nudge and not a diagnosis: how much sunlight you get and what you eat matter far more, so regular sun, vitamin-D-rich foods (oily fish, eggs, fortified dairy), or a supplement if a blood test shows you're low are the practical levers.

Tends toward higher vitamin D. You carry few of the common low-vitamin-D variants across these three genes, so from a genetic standpoint you tend to hold onto vitamin D a little better than average. This is only a small advantage, since sunlight and diet drive your actual level, so the usual habits of some sun and vitamin-D-rich foods still apply.

Intermediate vitamin D tendency. Your mix of the three common vitamin D variants sits in the middle, neither clearly low nor high. The genetic effect here is small either way, so your real vitamin D status depends mostly on sun exposure, skin tone, where you live and your diet. A blood test is the only way to know your level.

Evidence & sources

This panel reads GC (DBP), CYP2R1, DHCR7/NADSYN1.

Combines three common vitamin D genes (GC, CYP2R1 and DHCR7/NADSYN1). Together they explain only a small fraction of vitamin D variation, so a low or high genetic tendency is a gentle leaning, not a measurement. If one of these variants is missing from your file, the panel simply reads the ones it has. Only a blood test shows your actual level.

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