What is rs4257763 (SLC23A1) nd Why Does the Nutrient Zoomer Test for It?

Vitamin C transporter variant

rs4257763 is a single‑nucleotide variant in SLC23A1, the gene for the sodium‑dependent vitamin C transporter (SVCT1). It can influence how vitamin C is absorbed and cleared, so testing it helps explain individual differences in vitamin C status.

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rs4257763 (SLC23A1)

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About rs4257763 (SLC23A1)

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About rs4257763 (SLC23A1)

Overview and History

SLC23A1 encodes SVCT1, a membrane transporter that facilitates uptake of ascorbate (vitamin C) across epithelial surfaces, especially in the intestine and kidney. Variants in this gene, including rs4257763, are common genetic differences studied for their effects on nutrient handling rather than for causing disease. Researchers characterized the SLC23 family in the early 2000s when SVCT1 and SVCT2 were identified as the primary active transporters for vitamin C. SVCT1 is considered a key regulator of whole‑body vitamin C availability by controlling intestinal absorption and renal reabsorption.

Interpreting Highs and Lows

Genetic differences at rs4257763 are associated with shifts in transporter function and with patterns of circulating vitamin C when looked at across populations. Certain alleles have been linked to lower circulating vitamin C, which may reflect reduced intestinal uptake or increased renal loss; other genotypes are associated with average or higher levels. Interpreting any association requires the full clinical picture: dietary intake, blood vitamin C measurement, other nutrient transport genes, and metabolic markers in the Nutrient Zoomer are all important for understanding what a variant means for an individual.

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rs4257763 is included in the Nutrient Zoomer to capture inherited variation in vitamin C transport. It helps explain why two people with similar diets can have different blood vitamin C levels and supports interpretation of measured vitamin C and related metabolic markers for personalized nutrition planning.

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rs4257763 (SLC23A1) FAQs

What is rs4257763 (SLC23A1) and why is it important?

rs4257763 is a common genetic variant in the SLC23A1 gene, which encodes the SVCT1 transporter for vitamin C. SVCT1 helps move vitamin C from the gut into the bloodstream and conserves it in the kidney. Knowing if you carry variants at this site helps explain individual differences in vitamin C availability and related metabolic patterns.

What does it mean if my rs4257763 (SLC23A1) levels are low?

For a genetic marker, “low” generally refers to an allele linked to reduced transporter activity. Such an allele has been associated, in population studies, with lower circulating vitamin C, which could reflect reduced absorption or greater urinary loss. Interpretation should consider measured vitamin C, diet, and other Nutrient Zoomer results rather than the variant alone.

What does it mean if my rs4257763 (SLC23A1) levels are high?

An allele associated with higher transporter function may correlate with higher circulating vitamin C in population studies, but elevated blood levels can also come from recent intake or other factors. Genetic findings are one piece of the puzzle and require comparison with blood nutrient measurements and the broader panel for meaningful clinical context.

Why is this biomarker included in the Nutrient Zoomer?

rs4257763 is measured to reveal inherited differences in vitamin C transport that can explain discordance between intake and blood levels. Combined with direct vitamin C measurement and other nutrient and metabolic markers, it helps clinicians identify patterns of absorption, clearance, and cellular availability to support precision nutrition evaluation.

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