Can Vitamin D Offer Protection Against Cancer?

The importance of Vitamin D to the human body is beyond dispute.

A fat-soluble vitamin that is naturally present in very few foods, vitamin D is added to others and is available as a dietary supplement.

It is also produced endogenously when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis.

But what's the link between vitamin D and cancer risk?

Vitamin D is important for good health, growth and strong bones. Rickets, osteomalacia, depression, osteoporosis, cancers, diabetes, infections and auto-immunity, neurological conditions, oral health, respiratory and even mental disorders have been linked with Vitamin D deficiency.

Laboratory and animal indications, as well as epidemiological statistics, suggest that vitamin D standings could even affect cancer risk. Strong biological and mechanistic data indicate that vitamin D plays a role in the prevention of colon, prostate and breast cancers.

There have been a number of recent studies conducted to determine whether vitamin D is beneficial for those with cancer.

• An Irish study conducted in 2018 analysed data on almost 5,500 breast cancer patients aged 50-80. Research showed a 20% increase in survival among patients who took vitamin D supplements post-diagnosis, compared with those who did not.

• Higher circulating 25(OH)D correlated with a statistically significant, substantially lower colorectal cancer risk in women and non–statistically significant lower risk in men, according to a 2018 study.

• Subjects with vitamin D levels of less than 10 nanograms per millilitre (ng/mL) suffered from a 91% higher adjusted risk of liver cancer and a 67% greater risk of dying from chronic liver disease, compared with those whose blood levels were greater than 20 ng/mL, according to a 2018 study.

• A Japanese study, also published in 2018 in the British Medical Journal, found that "higher vitamin D concentration was associated with lower risk of total cancer.

These findings support the hypothesis that vitamin D has protective effects against cancers at many sites."

Cancer is not the only disease or condition vitamin D appears to help with. Millions of adults worldwide have – or are at risk of developing – osteoporosis, a disease characterised by low bone mass and a fundamental decline of bone tissue that intensifies bone brittleness and ominously escalates the risk of bone fractures.

Osteoporosis is regularly linked with poor calcium consumption, but scarce vitamin D contributes to osteoporosis by reducing calcium absorption.

A lack of vitamin D is highly common. Nutrient insufficiencies are typically the consequence of dietary failings, reduced absorption and use, augmented necessity, or greater-than-before excretion. A vitamin D deficiency can occur when customary ingestion is less than recommended levels over time, exposure to sunlight is limited, the kidneys cannot convert 25(OH) to its active form, or absorption of vitamin D from the digestive tract is scant.

According to analysis in the British Medical Journal, published in 2017, Vitamin D supplements could spare more than three million people from the cold and flus each year.

Although the official UK recommended intake is just 10mcg, many sources believe a higher quantity of Vitamin D is needed. Indeed, the Vitamin D Council advise that adults should aim to get 125mcg (5,000 i.u.) per day, whether from the sun, food, supplements or a combination of all three.