Vitamin D helps slow ageing - study

This is according to a new five-year study conducted by American scientists from Augusta University. They found that a daily intake of 2,000 IU of vitamin D helps to preserve telomeres - sections of DNA directly linked to cell aging, The Conversation reports.

What are telomeres?

Telomeres are "protective caps" at the ends of chromosomes that protect DNA from damage each time a cell divides. They shorten over time. When telomeres become too short, the cell loses its ability to divide and dies. Telomere shortening is associated with diseases such as cancer, heart disease, and osteoarthritis. Smoking, chronic stress, depression and inflammatory reactions also affect this process.

Vitamin D: not just for bones

Previously, vitamin D was known mainly for strengthening bones and preventing rickets. But it also supports immunity and, according to reviews, reduces the risk of respiratory infections - especially in people who are deficient. Some evidence also points to its potential role in preventing autoimmune diseases such as rheumatoid arthritis or multiple sclerosis.

Since inflammation accelerates telomere shortening, the anti-inflammatory properties of vitamin D may explain its positive effects on cellular aging.

The study involved 1,031 people aged about 65 years. Half of the participants took 2,000 IU of vitamin D daily, while the other half received a placebo. Telomeres were measured at the beginning, after two years and after four years. It turned out that those who took vitamin D had 140 base pairs longer telomeres than the placebo group. Considering that telomeres typically shorten by about 460 pairs in 10 years, the result can be considered significant.

It's not all that simple

Nevertheless, the researchers urge caution. Firstly, too long telomeres may also increase cancer risk, according to some reports. Second, the optimal dose of vitamin D has not yet been established. The study used a dose of 2,000 IU, while official recommendations are 600-800 IU per day. Some other studies claim that even 400 IU is enough to prevent colds.

The ideal dose probably depends on individual factors: vitamin D levels in the body, overall diet, and interactions with other nutrients.

Although the discovery looks promising, scientists emphasise: it is premature to hope that high doses of vitamin D will slow ageing. It's better to focus on proven ways: a balanced diet, regular physical activity, good sleep, quitting smoking and managing stress.

For those who are vitamin D deficient or at risk for osteoporosis, supplements are still recommended - their effectiveness is backed by decades of research. But it is too early to take them "just in case" to prolong youth.