A walking speed below 0.8 meters per second indicates an increased risk of falls (image: Pikisuperstar/Freepik)

Published on 01/19/2026

By Maria Fernanda Ziegler  |  Agência FAPESP – Vitamin D deficiency can be considered a warning sign for low mobility in old age. A study by researchers at the Federal University of São Carlos (UFSCar) in Brazil and University College London (UCL) in the United Kingdom revealed that older adults with vitamin D deficiency were at a higher risk of walking slowly. The results were published in the journal Diabetes, Obesity and Metabolism.

A slow walking speed of less than 0.8 meters per second (m/s) in older adults is an important indicator of mobility. It is associated with a loss of independence and an increased risk of falls, hospitalization, institutionalization, and death.

“Vitamin D is therefore an important marker for earlier identification of the risk of slow walking speed and serves as a warning sign for old age with possible mobility difficulties,” says Tiago da Silva Alexandre, a professor at the Department of Gerontology at UFSCar and author of the study, which was funded by FAPESP. “Since slow walking speed is associated with a higher risk of functional dependence and adverse outcomes, monitoring vitamin D levels, especially in older adults, should also be prioritized in various clinical settings and health services,” Alexandre points out.

The researchers analyzed data from 2,815 people aged 60 or older. The participants are part of the English Longitudinal Study of Ageing (ELSA), a longitudinal health study in England. Initially, only individuals with no walking speed-related problems were selected for the study. Blood vitamin D levels were assessed at the beginning of the study, and walking speed was reassessed over six years. This made it possible to correlate reductions in walking speed with vitamin D sufficiency, insufficiency, or deficiency.

The data showed a higher number of slowness cases in participants deficient in vitamin D. Having less than 30 nmol/L of vitamin D increased the risk of slowness by 22%, compared to having more than 50 nmol/L of vitamin D, which is considered sufficient. Nanomoles per liter (nmol/L) is a unit of measurement used to express the concentration of a substance in a volume of liquid. No association was detected between vitamin D insufficiency (between 30 and 50 nmol/L) and slowness.

The researchers emphasize that slow walking speed has multiple causes, one of which is vitamin D deficiency over a period of six years. “Vitamin D plays an important role in the musculoskeletal system because, when synthesized by sunlight, it acts on muscle cells by regulating the entry and exit of calcium, which allows muscle contraction, for example. Therefore, when there’s a vitamin D deficiency, this flow is impaired,” says Mariane Marques Luiz, a professor at UFSCar who conducted the research during her doctoral studies.

Luiz also points out that vitamin D deficiency triggers a reduction in muscle protein synthesis, a common problem associated with aging, which makes it more difficult for older adults to build muscle. Additionally, vitamin D deficiency has neurological effects, interfering with the protective effect on neurons and the speed of nerve impulse transmission. Luiz adds, “In addition to the muscular issue, vitamin D deficiency has repercussions on the central and peripheral nervous systems, compromising gait through the slow transmission of neural stimuli for walking.”

Vitamin D in old age

The study results proved that vitamin D deficiency is a risk factor for slow walking speed, regardless of other factors such as age, sex, race, education level, physical activity level, smoking status, and other diseases.

“As a very important indicator, its monitoring should be considered for maintaining healthy aging. But caution is needed as slow walking speed is a multifactorial problem, and excessive vitamin D supplementation is known to cause toxicity,” Alexandre points out.

In recent years, vitamin D has been in the spotlight due to its various health benefits. Recent studies have highlighted its role in enhancing the immune, cardiorespiratory, neurological, and musculoskeletal systems. However, it has also been the subject of fake news about supposed miracle treatments.

“It’s not that vitamin D is good for everything; it’s that it’s important for various organs and systems in the body. Virtually all cells in the body have vitamin D receptors. When the skin is exposed to the sun, a substance present in the deeper layers is activated by ultraviolet rays. This substance undergoes metabolic processes and is transformed into the active form of vitamin D. To act on tissues, this vitamin needs to bind to specific receptors. As these receptors are present throughout the body, vitamin D is able to perform its functions in several areas,” explains Mariane Luiz.

In old age, there is a natural reduction in the amount of vitamin D circulating in the blood. “As we age, there’s a reduction in the bioavailability of the precursor substance of vitamin D, which occurs due to the thinning of the skin. There’s also a decrease in the number of vitamin D receptors in the cells of different tissues, which reduces the skin’s ability to synthesize and distribute vitamin D to the tissues. That’s why monitoring is so important in this age group, as the age-related decline in vitamin D levels can decrease the physiological reserves of these systems, triggering various problems, including loss of mobility,” says the researcher.

The article “Is serum 25-hydroxyvitamin D deficiency a risk factor for the incidence of slow gait speed in older individuals? Evidence from the English longitudinal study of aging” can be read at dom-pubs.onlinelibrary.wiley.com/doi/full/10.1111/dom.16317. 

 

Source: https://agencia.fapesp.br/56984