Almost nobody was deficient. Yet low vitamin C went with slower walking.

Cross-sectional study. 5,028 people. one-time snapshot at the third health check, 2004-2011.

One snapshot in time. Nobody was told what to do. A clue, not proof.

Who: Adults aged 48-92 (median 67.5) from Norfolk, UK, in the EPIC-Norfolk cohort; 99.7% White; plasma vitamin C analysis n = 5,028 (2,786 women, 2,242 men), dietary analysis n = 5,877 (3,236 women, 2,641 men). Very few were vitamin C deficient (n = 14 below 11 umol/L)

• Walking speed (women)+10.6%good vs low vit C
• Walking speed (men)+4.4%good vs low vit C
• Grip strength (men)noneno clear link

More to know, from our read of the paper:

• Cross-sectional: vitamin C and physical tests measured at the same time, so direction is unknown (authors: 'the cross-sectional design limits the ability to determine causal relationships'). Linked, not proven
• Authors flag residual confounding: blood vitamin C may mark a generally healthier diet (fibre, other plant compounds) and lifestyle, including more physical activity, even though activity was adjusted for
• Supplement use was NOT available, so the study says nothing about vitamin C pills. Don't recommend supplements; don't recommend anything (no intervention tested)
• Non-fasting blood samples, which recent meals can affect (authors' limitation)
• Population almost entirely White British, aged 48-92; results may differ where deficiency is common (authors say possibly stronger)

Researchers measured blood vitamin C in 5,028 adults aged 48 to 92 in Norfolk, England, and tested their walking speed, grip and chair stands at the same visit. Women with good vitamin C levels walked about 11% faster than women with low levels, and men about 4% faster. Both were quicker at standing up from a chair; men's grip strength showed no clear link. Supplements were not measured, and it was a one-time snapshot: linked, not proven.

We read the abstract and the full text of this paper and checked every number on this page against it (18 facts, checked on 2026-10-29). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.