1 . Vitamin D was recognized a century ago as the cure for rickets, a childhood disease that causes weak bones. Then, in the early 2000s, a pile of studies suggested that low vitamin D levels could be a factor in cancer, cardiovascular (心血管) disease, Parkinson’s disease and so on. This simple vitamin seemed to be a cure for whatever troubled us. However, all these observational studies have a fundamental weakness: they can identify a co-occurrence between vitamin D and a disease, but they can’t prove there is a cause-and-effect relation.

To look at whether taking vitamin D had curative effects, Manson and her team started the world’s largest and most far-reaching randomized vitamin D trial. The study followed nearly 26,000 healthy adults, randomized to receive either 2,000 international units (IU) of vitamin D or a placebo (安慰剂), for an average of 5.3 years. The volunteers were almost evenly split between men and women, and 20 percent of the participants were black.

The results came as a shock. Not only did vitamin D not reduce rates of cancer or heart disease, but the trial also found that vitamin D did not prevent or improve cognitive function, or reduce the risk of bone fractures (骨折). The finding about fractures “was a real surprise to many people,” Manson says.

In 2011, the Institute of Medicine established an expert committee to conduct a thorough analysis of all existing studies on vitamin D and health. The committee concluded that the bone-strengthening benefits of vitamin D remain steady when blood levels reach 12 to 16 nanograms per millililter. They also found that there were no benefits to having levels above 20ng/ml. According to measurements of vitamin D levels in the general U. S. population, most had levels of 20 ng/ml or more in 2011. Levels have actually risen since then, meaning that most people don’t need to take extra vitamin D.

The ups and downs of vitamin D offer a lesson in humility. The relation between the vitamin and disease is far more complicated than it first seemed and a reminder that scientific understanding is always developing over time.

5 . New York University (NYU) surgeons have performed the world’s first transplant of an entire human eye, an extraordinary addition to a face transplant, although it’s far too soon to know if the man will ever see through his new left eye.

An accident had destroyed most of Aaron James’ face and one eye. His right eye still works. But the surgeons hoped replacing the missing one would produce better cosmetic (整容的) results for his new face. The NYU team is doing just that. James is recovering well from the dual (双重的) transplant last May and the donated eye looks remarkably healthy.

Today, transplants of the cornea (眼角膜) are common to treat certain types of vision loss. But transplanting the whole eye—the eyeball, its blood supply, and the critical optic nerve (视神经) that must connect it to the brain—is considered a moonshot in the search to cure blindness.

Whatever will happen next, James’ surgery offers scientists a window into how the human eye tries to heal. “We’re not claiming that we are going to restore sight,” said Dr. Eduardo Rodriguez, who led the transplant. “But there’s no doubt that we are one step closer.”

Some specialists had feared the eye would quickly become dry and wrinkled. However, when Rodriguez opened James’ left eyelid, the donated eye was fat and full of liquid. Doctors see good blood flow and no sign of rejection.

Now researchers have begun analyzing scans of James’ brain that detected some puzzling signals from that all-important but injured optic nerve. Dr. Jeffrey Goldberg, who has long studied how to make eye transplants a reality, called the surgery exciting. “It’s an amazing confirmation of animal experiments that have kept transplanted eyes alive,” he said. “The difficulty now is how to regrow the optic nerve, although animal studies are making progress.” He praised the NYU team’s “boldness” in even aiming for optic nerve repair and hopes the transplant will promote more research.

To write his own medical text, Li Shizhen referenced over 800 medical texts, countless books on history and geography, and works of literature. He even studied the complete works of many ancient poets, from     1     he selected a surprising number of verses about medicine. However, the greatest issue he encountered was the widespread     2    (inconsistent) in the use of drug names. Realising the importance of field research outweighed     3    of extensive reading, in 1565 Li travelled far and wide into the mountains and wilderness. He covered what are today’s provinces of Hunan, Jiangxi, Anhui and Jiangsu, and many other places.

After over a decade of field research, Li     4    (successful) completed the first draft of his masterpiece, Bencao Gangmu, or the Compendium of Materia Medica in 1578. He revised     5     work at least three times right up until his death in 1593.

Since its first publication in 1596, the book     6    (receive) world-wide recognition. British naturalist Charles Darwin acknowledged the book     7     an “ancient Chinese encyclopedia.” In 2011, the book    8    (list) on the UNESCO Memory of the World Register. In 2017, an international conference was held in Beijing     9    (celebrate) Li’s 500th birthday.

Today, there are a     10    (grow) number of international exchanges centering on Li Shizhen and his book, and many people around the world can still find the wisdom of human development in this ancient classic.

9 . Thousands of lives have been saved by giving blood-thinning drugs to people with a heart condition that leaves them at risk of a stroke(中风), according to the head of the NHS.

Since January 2022 about 460,000 people in England who suffer from atrial fibrillation(AF)- a dangerously irregular heart rate-have begun taking one of four anticoagulant(抗凝血剂) drugs that are proved to reduce stroke risk. Speedy introduction of the drugs has kept 4,000 people alive who would otherwise have died and prevented about 17,000 strokes, according to Amanda Pritchard. Strokes kill about 27,000 people a year in England and lead to about 120,000 being taken to hospital.

A drive to encourage take-up of the drugs means 90% of the 1.5 million people in England with AF are using them. That should result in fewer strokes, which are a leading cause of death and disability, given that AF causes about one in five strokes.

“The rapid introduction of these drugs is a big step forward in providing the best possible care for patients with heart disease”, Pritchard, the leader of NHS(National Health Service) England, will say in a speech today at the King’s Fund health experts’ yearly conference.

The drugs, called direct oral anticoagulants, help stop blood from clotting(凝血), therefore reducing the risk of a clot developing and causing a stroke. In 2021 the National Institute for Health and Care Excellence recommended that doctors use four anticoagulant drugs.

Dr Maeva May, the Stroke Association’s director, thought the widespread use of the drugs as “fantastic news”, because AF accounts for one in five strokes and strokes in people with AF are more likely to result in death or serious disability.

NHS England has used its spending power to cut deals with the makers of the four drugs, which has made them much more widely available. The British Heart Foundation praised the NHS’s “great progress towards its goal of reducing stroke deaths”.