I Ate a ‘Sunshine Menu’ Created Specially for Vitamin D-Starved Brits

It's official: the British weather is so bad that it might actually be making us ill. Lack of sunshine means a lack of vitamin D, which means we struggle to process calcium, which means that half of older women in the UK are likely to have problems with osteoporosis and brittle bones. And then there's the possibility of it having an impact on whether we develop diabetes, heart disease, and multiple sclerosis.

Our dreary skies are so much of a public health concern that last week, after years of reviewing the evidence from research, the Scientific Advisory Committee on Nutrition (SACN) recommended that we ensure we're getting at least 400 International Units (IU) of vitamin D every day (the equivalent of 10 micrograms). To make sure we do, they suggest we take a supplement.

"It's quite unusual," says nutritionist Fiona Hunter when I speak to her about Britain's national vitamin D deficiency. "Usually scientists say it's always better to get your vitamins and minerals from food. But in this case, it's difficult."

There are basically three things you can eat to make sure you get your quota of edible sunshine: egg yolks, oily fish, and liver.

"It's not a huge range," Hunter notes. "Oily fish like sardines, salmon, and mackerel are some of the best sources. The problem is we don't actually eat much fish at all in this country."

According to Paul Greening, head chef at London Japanese restaurant Aqua Kyoto, Britain ought to look East to learn how to get the nutrition we're missing from lack of UV rays.

"The Japanese diet is high in vitamin D," he explains. As a former microbiologist, Greening has taken it upon himself to apply scientific rigour to creating a "sunshine menu."

"Since we were using Japanese ingredients anyway, making a 'sunshine menu' was a natural thing to do," he says. "I come from New Zealand where we get a lot of vitamin D, but there's just not enough in the British weather. I created it to give people an understanding of what you can eat to get enough."

But sunshine isn't the only source of vitamin D.

"People used to think you could get enough from sunlight," says Hunter. "But the sun is at the wrong axis in the winter months for us to get the right wavelengths, we work inside more, and when we're outside, we're wearing sunscreen. We just can't make enough."

So Greening measured the amount of vitamin D in different foods to construct a meal that could help us thrive in the darker months of the year—or just the underwhelming British summer.

Unsurprisingly, it involves a lot of fish, beginning with sashimi, which I watch head chef Yackshin Jin prepare in true Japanese style, with an inordinate amount of precision and care.

"The first dish we came up with was sashimi made with rich oily fish," Greening explains. "We've got mackerel, salmon, and tuna. Molluscs are high in vitamin D as well, so we use Orkney island scallops, and then there's cod liver."

Liver. The Silence of the Lambs did its reputation no favours and it's something I always hesitate over before forking it up and eating. But Greening sees no reason for us to hesitate.

"If you look at the gram weight, cod liver is one of the best things you can eat," he says. "Eighty-five grams of cod liver will give you 2,000 IU of vitamin D. A piece of salmon, you'll only get 700 IU. Liver has three times the amount that fish does."

Meaning you only need to eat a little to meet the SACN recommendation. In this instance, the liver isn't being served with "fava beans and a nice Chianti," Hannibal Lecter-style, but thinly sliced with lemon.

Jin is gently taking every piece of fish, and almost cradling it as he precisely slices and arranges it on ice, with carefully placed edible leaves and flowers, checking the presentation to make sure the colours are in balance with one another. It has taken him twenty years to master the art of sashimi.

So we have fish and liver, which leaves eggs. Jin adds these to the sashimi platter as tamago, an omelette made with mirin, sake, soya, and ichiban dashi.

"The dashi also has some vitamin D," says Greening. "Because it's made from skipjack tuna that's been smoked and dried, and left until it has mould on it and then grated."

Jin carefully slices the omelette into shape and adds it to the mix. It's beautiful. Fortunately, it's not necessary for us non-sushi masters to apply the same precision to our preparation (given my knife skills, the amount of prep would mean I might never get round to actually eating any vitamin D). Well-sourced fish that you can be certain is safe to eat raw as sashimi, however, is extremely important. No one wants to get botulism in the pursuit of extra vitamin D.

That's course number one. But there's more. Greening is determined to make sure I get my full quota ("You should be walking out of here as if you've had an hour's worth of sunshine") and presents a second dish: homemade soba noodles with katsuobushi, lacto-fermented vegetables, and mentaiko. The noodles are made from sweet potato (a source of small amounts of vitamin D) and the mentaiko is marinated pollock and cod roe—both vitamin D to the max.

"We've got lots of cod oil in there, and some more cod liver," he says. "The fermented vegetables are full of probiotics. Basically if you eat this all the time, you can live forever."

Of course, that's not true and you have to take care not to OD on vitamin D—too much of it and you can absorb too much calcium which can knacker your kidneys and your heart—but there's a reason why Mediterranean diet (with lots of sardines and pilchards) and the Japanese diet (also full of fish) have a longstanding reputation for being models to emulate.

One thing's for certain. I've definitely eaten my vitamin D quotient for the day, if not the week, in this one sitting.

Outside it's a typical London July—mild but mizzling. But I don't care. After the plates I've just eaten, I'm literally fuelled by internal sunshine.