研究发现维生素D可能有助于延缓衰老

　　

一项临床试验表明，维生素D可能通过保护端粒来延缓细胞衰老。研究人员敦促谨慎用药，并强调生活方式是健康老龄化最可靠的途径。

最近的一项研究表明，维生素 D 补充剂可能有助于保护我们染色体上的保护帽，从而影响衰老的速度，这让人们希望“阳光维生素”能够支持更健康的长寿。

研究人员报告称，每天服用 2,000 IU（国际单位，一种标准维生素计量单位）维生素 D 有助于保护端粒。端粒是染色体末端的小结构，其作用类似于鞋带的塑料头，在细胞分裂过程中保护DNA免受损伤。

我们46条染色体的末端都有一段端粒，每次细胞分裂时，端粒都会逐渐缩短。一旦端粒变得极短，细胞就会失去分裂能力，最终死亡。

端粒缩短与多种主要的年龄相关疾病有关，包括癌症、心脏病和骨关节炎。吸烟、慢性压力和抑郁等因素似乎会加速这一过程，而体内的炎症过程也会导致端粒缩短。

除了强健的骨骼

维生素D因其在骨骼健康中的作用而被广泛认可，尤其是在帮助人体吸收钙方面。对于儿童、青少年以及肤色较深或日照较少的人来说，充足的维生素D摄入尤为重要，以确保骨骼的正常生长和维持。

但维生素D也能增强我们的免疫系统。一项证据审查发现，维生素D补充剂可以减少呼吸道感染，尤其是对缺乏维生素D的人群。

早期研究甚至表明它可能有助于预防类风湿性关节炎、狼疮和多发性硬化症等自身免疫性疾病，但还需要进行更多的试验。

由于炎症会损害端粒，维生素 D 的抗炎作用可以解释其保护作用。

在临床研究中测试维生素 D

In this recent study, from Augusta University in the US, the researchers followed 1,031 people with an average age of 65 for five years, measuring their telomeres at the start, after two years, and after four years. Half took 2,000 IU of vitamin D daily, while the other half received a placebo.

The results showed that telomeres were preserved by 140 base pairs in the vitamin D group, compared with a placebo. To put this in context, previous research found that telomeres naturally shorten by about 460 base pairs over a decade, suggesting vitamin D’s protective effect could be genuinely meaningful.

This isn’t the first promising finding. Earlier studies have reported similar benefits, while the Mediterranean diet – rich in anti-inflammatory nutrients – has also been linked to longer telomeres.

The catch

But there are some important points to note. Some researchers warn that extremely long telomeres might actually increase disease risk, suggesting there’s a sweet spot we don’t yet understand.

There’s also no agreement on the right dose. The Augusta researchers used 2,000 IU daily – much higher than the current recommended intake of 600 IU for under-70s and 800 IU for older adults. Yet other research suggests just 400 IU might help prevent colds.

Experts say the optimal dose probably depends on individual factors, including existing vitamin D levels, overall nutrition, and how the vitamin interacts with other nutrients.

Although these findings are exciting, it’s too early to start popping high-dose vitamin D in the hope of slowing aging. The strongest evidence for healthy aging still points to the basics: a balanced diet, regular exercise, quality sleep, not smoking, and managing stress, all of which naturally support telomere health.

However, if you’re deficient in vitamin D or at risk of poor bone health, supplements remain a sensible choice backed by decades of research. As scientists continue unravelling the mysteries of aging, vitamin D’s role in keeping our cellular clocks ticking may prove to be just one piece of a much larger puzzle.