Though low vitamin D (sunshine vitamin) levels do not cause non-skeletal diseases, decreases in the vitamin levels are a marker of deteriorating health, new study suggests.

Researchers examined over 290 studies of adults ages eighteen and older that actually showed a moderate to even a high risk of various medical conditions when Vitamin D levels were low, according to the study report published in the Lancet Diabetes and Endocrinology journal.

The analysis showed a positive link between vitamin D deficiency and disorders such as infectious diseases, cardiovascular illnesses, various mood disorders and glucose-metabolism problems.

Study carried out at the International Prevention Research Institute in French city of Lyon reveals that high vitamin D could reduce the risk of cardiovascular events by up to 58%, diabetes by up to 38% and colorectal cancer by up to 33%.

A vitamin D level less than 25nmol/L in the blood is a deficiency, but experts increasingly believe that “lower than 60nmol/L can also be damaging to health.”

In some countries such as the UK, vitamin D supplements are recommended for groups at higher risk of deficiency, including all pregnant and breastfeeding women, children under five years old, people aged over 65, and people at risk of not getting enough exposure to sunlight.

People with dark skin, such as people of African-Caribbean and South Asian origin, and people who wear full-body coverings, as well as pale-skinned people are also known to be at higher risk.

“It has been known for almost a century that vitamin D supplements given to those with deficient vitamin D levels results in improved bone health, preventing hypocalcemic seizure and rickets,” said Dr Colin Michie, consultant senior lecturer in pediatrics and chair of the nutrition committee at the Royal College of Paediatrics and Child Health.

It is important to provide appropriate supplements such as vitamin D for the groups in need to improve bone health, he recommended.

Many experts believe that enough vitamin D can be supplied by being exposed to the sun for 10 to 15 minutes a day. It is also found in certain foods like oily fish, cheese, eggs and breakfast cereals.