Researchers studied 120 older South Asian women in England to see if vitamin D affects muscle strength and ability to move around. They found that nearly half of the women didn’t have enough vitamin D in their blood. Women with healthy vitamin D levels were better at standing up from chairs and keeping their balance compared to those with low vitamin D. However, vitamin D didn’t seem to affect hand grip strength. The study suggests that vitamin D supplements might help older South Asian women maintain their leg strength and balance, which is important for staying independent and avoiding falls.

The Quick Take

  • What they studied: Whether having enough vitamin D in the blood helps older women stay strong and mobile, especially in their legs and ability to balance
  • Who participated: 120 women aged 60 and older from Indian and Pakistani backgrounds living in northern England. The average age was 66 years old.
  • Key finding: Women with adequate vitamin D levels performed significantly better on tests of leg strength and balance compared to women with low vitamin D. About 47% of the women studied didn’t have enough vitamin D, but 86% of those taking vitamin D supplements had healthy levels.
  • What it means for you: If you’re an older South Asian woman, getting enough vitamin D through supplements or sunlight may help you stay stronger in your legs and maintain better balance. This could reduce your risk of falls and help you stay independent longer. However, talk to your doctor before starting supplements, as this study shows a connection but doesn’t prove vitamin D is the only factor.

The Research Details

This was a cross-sectional study, which means researchers looked at a group of women at one point in time rather than following them over months or years. The researchers measured vitamin D levels using a blood test from a finger prick sample and tested muscle strength and function using simple, practical tests that older adults can do safely. The tests included standing up from a chair multiple times, holding grip strength, walking and turning, and balance exercises. They then looked at whether women with different vitamin D levels performed differently on these tests.

The study included 120 community-dwelling women aged 60 and older from Indian and Pakistani backgrounds living in the North of England. About 41% of the women were already taking daily vitamin D supplements. The researchers used statistical analysis to determine if differences in vitamin D levels were connected to differences in muscle strength and function.

This research approach is important because it focuses specifically on South Asian women, a group that has been understudied in vitamin D research. Most previous studies looked at white populations, so we didn’t know if the same vitamin D effects applied to other ethnic groups. South Asian women may have different vitamin D levels and different responses to vitamin D because of factors like skin tone, cultural clothing practices, and dietary differences. By studying this specific group, researchers can provide more relevant health information for South Asian communities.

This study has some strengths: it used accurate blood tests to measure vitamin D, it tested multiple aspects of muscle function, and it focused on a population that needed more research. However, because it’s a cross-sectional study, it shows a connection between vitamin D and muscle strength but can’t prove that low vitamin D causes weak muscles—other factors could be involved. The study size of 120 women is moderate, which means the findings are suggestive but would benefit from confirmation in larger studies. The study was conducted in one region of England, so results may not apply to all South Asian women everywhere.

What the Results Show

The study found that 47% of the women had inadequate or deficient vitamin D levels (below 50 nmol/L). Among women taking vitamin D supplements, 86% had healthy vitamin D levels, compared to only 32% of women not taking supplements. This shows that supplements are very effective at raising vitamin D levels in this population.

Women with adequate vitamin D performed significantly better on lower body strength tests. Specifically, they were better at standing up from a chair once (single chair stand test), standing up and sitting down repeatedly (repeated chair stand test), and maintaining balance. The differences were statistically significant, meaning they were unlikely to be due to chance.

Interestingly, vitamin D status did not affect hand grip strength or the timed up and go test (a test of walking and turning ability). This suggests that vitamin D may be particularly important for lower body strength and balance rather than upper body strength or overall mobility.

The study found that vitamin D supplements were very effective in this population—women taking supplements were much more likely to have adequate vitamin D levels. This is important because it shows that supplements can work well for South Asian women living in northern climates where there is less sunlight. The fact that vitamin D affected some muscle tests but not others suggests that vitamin D’s effects on muscle may be specific to certain muscle groups or types of movement, particularly those involving the legs and balance.

Previous research in mostly white populations suggested that vitamin D affects overall muscle strength and function. This study partially confirms that finding but shows that the effect may be more specific to lower body strength and balance. The high rate of vitamin D deficiency in this population (47%) is consistent with other research showing that South Asian populations living in northern climates have higher rates of vitamin D deficiency. The effectiveness of supplements in this study aligns with other research showing that vitamin D supplementation can improve vitamin D status.

This study has several important limitations. Because it only looked at women at one point in time, we can’t know if low vitamin D caused the weak muscles or if weak muscles led to less activity and lower vitamin D. The study only included women from Indian and Pakistani backgrounds in one region of England, so results may not apply to all South Asian women or to men. The study didn’t measure other important factors that affect muscle strength, like physical activity level, diet quality, or other health conditions. With only 120 participants, the study is relatively small, which means some findings might not hold true in larger groups. Finally, the study couldn’t determine the ideal vitamin D level for muscle health in this population.

The Bottom Line

Based on this research, older South Asian women may benefit from maintaining adequate vitamin D levels through supplements or increased sun exposure. Current guidelines recommend 600-800 IU of vitamin D daily for adults over 50, though some experts suggest higher amounts. The evidence from this study is moderate—it shows a connection between vitamin D and leg strength but doesn’t prove vitamin D is a cure for weakness. If you’re concerned about muscle strength or balance, talk to your doctor about vitamin D testing and supplementation as part of a broader approach that includes exercise and good nutrition.

This research is most relevant to South Asian women aged 60 and older, particularly those living in northern climates with limited sunlight. It’s also relevant to healthcare providers caring for this population. The findings may also apply to other older women and possibly men, though more research is needed. If you have muscle weakness, balance problems, or are at risk for falls, discussing vitamin D with your doctor is worthwhile. However, if you already have adequate vitamin D levels, this study doesn’t suggest you need more.

If you start taking vitamin D supplements, it typically takes 4-8 weeks to see changes in blood vitamin D levels. Improvements in muscle strength and balance may take longer—usually 8-12 weeks or more of consistent supplementation combined with physical activity. Don’t expect immediate results; think of vitamin D as one part of maintaining strength as you age.

Want to Apply This Research?

  • Track weekly vitamin D supplement intake (yes/no) and monthly simple balance tests like standing on one leg for 30 seconds or counting how many times you can stand up from a chair in 30 seconds. Record any changes in energy, balance confidence, or ability to do daily activities.
  • Set a daily reminder to take a vitamin D supplement at the same time each day (such as with breakfast). If you’re not taking supplements, use the app to log sun exposure time and discuss vitamin D testing with your doctor. Pair supplementation with a simple home exercise routine focusing on leg strength and balance.
  • Use the app to track vitamin D supplement adherence weekly and perform simple functional tests monthly (like the chair stand test or balance test). Note any changes in daily activities like climbing stairs, walking distance, or confidence in balance. Share this tracking data with your healthcare provider at annual checkups to assess whether supplementation is helping.

This research shows a connection between vitamin D and muscle strength in older South Asian women but does not prove that vitamin D supplements will prevent muscle weakness or falls in all individuals. Vitamin D supplementation should not replace medical advice from your healthcare provider. Before starting any new supplement, especially if you take medications or have health conditions, consult with your doctor. This study was conducted in one region and may not apply to all populations. Individual results vary based on genetics, overall health, physical activity, and diet. If you experience muscle weakness, balance problems, or falls, seek evaluation from a healthcare professional to identify all possible causes.