- About 1 billion people globally have a vitamin D deficiency.
- Researchers from the University of South Australia have found a causal relationship between vitamin D deficiency and increased mortality risk.
- Scientists also found a person’s risk of all-cause mortality increased by 25% if their vitamin D level was in the deficiency range.
Vitamin D plays an important role in a person’s overall health, including building
Although vitamin D is easily obtained through sun exposure and eating the right foods, it is possible to have a vitamin D deficiency.
Researchers estimate about
In a new study, scientists from the University of South Australia found evidence of a causal relationship between vitamin D deficiency and increased mortality risk.
This study was recently published in the journal Annals of Internal Medicine.
Vitamin D is an essential nutrient required for good health and plays an important role in:
- protecting bones from osteoporosis
- supporting the body’s immune system
- assisting cell growth
The body naturally makes vitamin D from sun exposure and receives vitamin D from foods high in the nutrient, including:
- vitamin D-fortified juices, dairy, and plant-based dairy products
- cod liver oil
- fatty fishes, including salmon, tuna, and mackerel
- beef liver
- egg yolks
Sometimes a person cannot naturally obtain all the vitamin D they need. A doctor can determine how much vitamin D a person has with a
- If a person has between 30-49 nmol/L (nanomoles per liter) of vitamin D in their blood, they are considered at risk of inadequacy.
- Under 30 nmol/L or less, the person is at risk for vitamin D deficiency.
In addition to blood test readings, symptoms of vitamin D deficiency include:
- bone fragility, osteoporosis, or both
- bone pain
- muscle weakness, pain, or twitching
- stiff joints
If a person has low levels of vitamin D, they may need to take a vitamin D supplement.
According to Dr. Elina Hyppönen, director of the Australian Centre for Precision Health at the University of South Australia and senior author of the new study, the research team wanted to evaluate whether higher vitamin D status can lower the risk of premature mortality and whether this effect is similar for people who have low vitamin D levels and for these who already have sufficient concentrations.
For the study, researchers examined data from more than 300,000 adult participants of the U.K. Biobank.
Scientists used a technique called
Upon analysis, researchers found over a 14-year time span that a person’s death risk decreased significantly when their vitamin D levels increased.
Scientists also reported an association between lower vitamin D levels and deaths caused by:
What’s more, the research team found a person’s risk of all-cause mortality increased by 25% if their vitamin D level was in the risk of deficiency range of 25 nmol/L, compared to participants with a vitamin D level of 50 nmol/L.
In this study, researchers found a “causal relationship” between vitamin D deficiency and increased mortality risk.
Dr. Hyppönen explained that a causal relationship means it is a relationship researchers believe to be “true” rather than a mere association.
“The genetic method which we use can overcome many of the methodological issues that can commonly affect findings from other types of observational studies, making them less reliable.”
– Dr. Elina Hyppönen, senior author of the study
Medical News Today also spoke about the research with Dr. Scott Kaiser, a geriatrician and director of geriatric cognitive health for the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, CA, who was not involved in the study.
He said with the techniques and data used, the researchers were able to perform a virtual clinical trial where a real-life trial might not be feasible or even ethical.
“We know it’s bad for you to have vitamin D deficiency, so how can you then ethically cause people to be vitamin D deficient to just study them compared to people who receive vitamin D supplementation?” he questioned.
Dr. Hyppönen noted this is not the first study to find evidence of a causal relationship between vitamin D deficiency and mortality risk.
“It is safe to say that this is the most comprehensive study to date, and for example, this is the first study to look into respiratory disease or to include sensitivity analyses that confirm the relevance for non-white ethnic groups.”
Dr. Hyppönen and her research team believe their findings highlight the need to follow national vitamin D intake guidelines to make sure a person’s vitamin D levels do not fall too low.
“The key is in the prevention. It is not good enough to think about vitamin D deficiency when already facing life-challenging situations when early action could make all the difference,” she said.
Joshua Sutherland, a Ph.D. student at the Australian Centre for Precision Health at the University of South Australia and first author of this study, agreed.
“While there are specific mechanisms via which vitamin D can promote better health regarding each of the cause-specific diseases we assessed — the ultimate role of vitamin D in life-challenging scenarios is likely promoting the ability to retain, at least, the minimal physiologic reserves required to sustain life,” he explained. This is because
vitamin D receptorsare found throughout the body, and because of this, many regulatory systems in the body rely on sufficient levels of the vitamin.”
– Joshua Sutherland, first author of the study
For people who are worried about their vitamin D levels, Dr. Kaiser said they should speak with their healthcare professional. He also stated older adults are at a significantly increased risk for vitamin D deficiency for a number of reasons.
“A lot of older people get less sun exposure — people may be indoors more,” he explained.
“As we get older, our skin is not as efficient and effective in synthesizing the
“It’s really important if you’re older or for your older loved ones to be particularly vigilant about the risk of vitamin D deficiency and being proactive about ensuring you have enough vitamin D.”
– Dr. Scott Kaiser, geriatrician