The amount of supplements offered in local pharmacies and supermarkets is often enough to grant them their own aisle, full of brightly-colored bottles of all shapes and sizes promoting the wellness of hair and nails, the heart, sleep or bones. There are options for men and women, kids and “over 50s” in pills, powders or gummy formulations. Decades of research shows that getting the right amount of certain vitamins and minerals in the diet can ward off diseases, and dietary guidelines serve as the most accurate estimate we have for what the body needs to stay healthy.

But some say more research is needed to fully understand sex differences in how female and male bodies need and use these nutrients across the life cycle. As a result, some are calling for improved recommendations that take a closer look at the role that sex, hormonal changes, and body composition play into these nutritional needs. 

“Women live longer, they experience different things like pregnancy and lactation, menstruation and menopause, and they have different disease risks,” said Dr. McKale Montgomery, a nutritionist at Oklahoma State University. “But so often the difference between the men versus women’s [supplements] is the color of the bottle and not what is inside.”

Although people had been using herbal medicines to supplement nutrients in their diet for centuries, Polish biochemist Casimer Funk is credited with coining the term “vitamins” in 1920, referring to the substances not produced in the body that we supplemented by diet. (“Vita” means “life” in Latin and “amine” is a nitrogenous substance necessary for biological life.) Funk’s research also showed that the lack of certain vitamins would cause illness, including a disease called pellagra when the body lacked vitamin B3 and scurvy when it lacked vitamin C. 

This work culminated in nutritional guidelines in the U.S. called the Dietary Reference Intake (DRI) values published at the turn of the 21st century that identify the amount of dozens of vitamins, macronutrients and minerals the body needed. 

Several sex differences have been well-researched and are reflected in the guidelines. Women of reproductive age are recommended to take more iron at certain ages, and women, particularly in the postmenopausal period of life, are recommended to take more calcium for bone health. Men, on the other hand, are recommended to take more magnesium and zinc. In general men are recommended to take a greater quantity of many vitamins simply based on differences in body composition.

However, some have called for more research in women specifically in the dietary supplement space, said Dr. Abbie Smith-Ryan, a professor of exercise physiology at UNC Chapel HIll. Although women consume more supplements than men, supplement use hasn’t been as well studied in women, she explained.

“The majority of data, if there is data, is done in young men for many reasons,” Smith-Ryan told Salon in a phone interview. “That doesn’t mean that everything needs to be at different doses, but at the very minimum, we need to understand: Should those be recommended at a different dose or with different ingredients to enhance absorption, or some of those things.”

The National Institutes of Health acknowledged the need for more nutritional research for women in its 2020-2030 strategic plan, which listed nutritional differences in women, along with differences in nutritional needs during pregnancy and lactation and across a woman’s life cycle as some of its research priorities.

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“Nutrition plays an important role in many diseases and conditions that primarily affect women or that affect women differently than men,” it states. “Inherent within this plan and its implementation are research approaches and activities that address the roles of sex and gender in health and disease; promoting participation of women in clinical nutrition research; and integrating sex as a biological variable in basic, preclinical, and translational nutrition research.”

Instead of comparing men and women to understand differences in nutritional needs, it might be more useful to study how nutritional needs vary across a woman’s life cycle, Smith-Ryan added. 

“No two women have the same menstrual cycle or hormone profile … so the standardization is much harder and requires more time and money to capture,” she said. 

One particular population that nutritional differences are more pronounced is athletes, in whom getting the right nutrients can also reduce the risk of injury. While female athletes are less likely to not get adequate nutrients, they are also more likely to see the consequences of that, Smith-Ryan said. 

“Anytime you add in that extra stress and those extra caloric needs from exercise, you see more of an impact, meaning, if you’re low on vitamin D or iron, you’re going to feel that,” Smith-Ryan said. “Whereas, if you’re more of a sedentary individual, you may not feel those as much because you’re not stressing the body the same way.”

There is also limited research available on which supplements might help women during the perimenopause part of life in particular. Some evidence suggests B12 might be helpful to the nervous system and vitamin D is helpful for promoting bone growth. Magnesium might help with sleep problems, although the research behind many of these links is thin and the recommendations for these supplements don’t currently differ by sex for this age group.

“Refining our recommendations for that decade would be really helpful,” Smith-Ryan said.

Vitamin D and calcium have been recommended among older adults to promote brain and bone health, especially among women who are affected by osteoporosis at four times the rate as men.

However, a draft recommendation by the United States Preventive Services Task Force released last month actually recommended against taking these two supplements at this age for both sexes for the purpose of reducing fractures. Although the agency clarified that supplementation with vitamin D and calcium could still be important for this age group for other reasons, some disagreed with the recommendation, noting that it didn’t take into account individual differences in whether people had vitamin D deficiencies.

“Dismissing supplementation as unnecessary for the general population undermines its value for those who need it most,” said Dr. Andrea Wong, the senior vice president of scientific and regulatory affairs at Council for Responsible Nutrition, a trade organization that represents many supplement manufacturers, in a statement.

In general, nutritional changes to help menopause would work better if they began long before menopause anyways, said Dr. Mary Scourboutakos, a nutritionist at Eastern Virginia Medical School. For example, peak bone mass is determined in the teenage years, meaning vitamin D and calcium intake many years before menopause is what is important for bone health at that time, she said. 

“We tell women when they’re 60 years old that their bone mass is low and try to pump them full of calcium and vitamin D,” Scourboutakos told Salon in a phone interview. “But the reality is, it’s the calcium and vitamin D they didn’t have in their teenage years that lands them in this place in their 60s.”

While drugs are used to treat illness, nutrition’s purpose is generally to prevent it, Scourboutakos said. However, this operates in a different research paradigm than how the effectiveness of drugs are demonstrated. While drug research takes sick people to determine whether a drug works, supplement research often takes healthy people and sees whether supplements can prevent illness.

“It’s easier to prove that you treated something than if you prevented something, and nutrition often works over years and decades, so it’s hard to get research to fund such a study,” Scourboutakos said. “Everything about our scientific method makes it hard to prove these sorts of things.”

Supplements are regulated for safety but not efficacy by the 1994 Dietary Supplement Health and Education Act, which is enforced by the Food and Drug Administration. The FDA and the Federal Trade Commission monitor companies to ensure they are actually selling what is being advertised, said Steve Mister, president and CEO of the Council for Responsible Nutrition.

“We have our own requirements that I would classify as being somewhere between those for food and those for drugs,” Mister told Salon in a video call.

The way the current regulations work provides the industry with greater flexibility so that it can react more quickly to changes in research, Mister said.

“It’s left to the market to create the variability in formulations,” Mister said. “That’s the beauty of the law that allows us to have some flexibility in how we develop the formulas for the products.”

Still, others have called for more regulations on supplements as the number of people taking them has exploded in recent years — with as many as 4 in 5 people reporting using them at some point in their lives. 

In pregnancy, women are recommended to take prenatal vitamins to ensure the body gets the right amount of folate, Omega-3 oils, and choline, among other vitamins like iron, vitamin D, and calcium. Although this population is one that has been studied to determine the benefit of these supplements, recent research has shown that many of these essential nutrients are missing from some products on the shelves.

One study found none of close to 50 samples of commercially available prenatal vitamins contains all of the recommended supplements for pregnant women, and up to 27% had less than the recommended amount of folate, which has been shown to protect against birth defects.

Ultimately, it’s largely up to the individual to stay up-to-date with their nutrient needs and make sure they check nutritional labels to ensure they are getting what they need from the supplements they do or not decide to purchase.

“A lot of time women don’t get that support or our health care providers don’t know the data,” Smith-Ryan said. “We need to encourage women to take care of themselves and advocate for themselves.”

A Genuine Tea Experience in a World Heritage Setting

The city of Uji, Kyoto, is well known for Byōdōin, a Buddhist temple listed as a UNESCO World Heritage site. Nearby is another popular tourist site, though—one where visitors can have a genuine sadō​ (tea ceremony) experience. This is Taihōan, a tea house operated by the Uji municipal government. It sits just across from the famed temple’s Phoenix Hall, as befits its name, which literally means “hermitage opposite the phoenix.”

Visitors pass through a rustic gate to reach Taihōan. (© Fujiwara Tomoyuki)

Visitors can watch and drink matcha (powdered green tea) from Uji, famed for its tea farms, prepared and served in the sadō tradition. The tea is accompanied by a seasonal Japanese sweet and a simple explanation of the tea ceremony and its steps provided by a sadō master.

The tea is prepared with soft water boiled slowly in an iron kettle heated over charcoal. Tea is served in raku teabowls, handcrafted in Kyoto. The bowls are chosen to match the season—for example, a design featuring heads of rice for October, when rice is harvested.

A bowl of matcha is served at Taihōan. (© Fujiwara Tomoyuki)

The tea experience requires reservations in advance. After watching the tea master prepare a bowl of tea, participants enjoy traditional sweets before trying their hand at whisking matcha themselves. The tea masters, who change daily, hail from various sadō schools, including the mainstays, Urasenke and Omotesenke. Repeat visitors may notice the differences in each school’s techniques.

The main approach to Byōdōin is lined with old purveyors of tea, cafés, restaurants, and sweets shops, and packed with tourists meandering the street with a matcha latte, ice cream, or other treat in hand. Tea is available in all forms—loose leaf, powder, and teabags among them—and in all price brackets, and many businesses have their own educational exhibits.

In November 2024, the local newspaper Kyoto Shimbun reported that the explosion in the popularity of Uji matcha tea among foreign tourists was causing shortages. Some stores have apparently begun imposing limits on the amount each shopper can purchase.

The street approaching Byōdōin is lined with tea houses and traditional confectioners. (© Fujiwara Tomoyuki)

Two Factors that Sparked a Boom

The Made in Uji brand has now gained global recognition. Its popularity can be traced to two factors.

The first was the so-called Häagen-Dazs Shock of 1996. In that year, the US ice cream manufacturer released a green tea product containing matcha, which led to a jump in the production and cost of the tencha used to make the powdered tea. It also touched off a boom in matcha-flavored sweets. Then, in 2000, coffee chain Starbucks began selling matcha-flavored drinks. Its popularity spread globally, causing the so-called Starbucks Shock, further boosting matcha sales.

Since then, matcha’s popularity has only increased: According to Japan’s Ministry of Agriculture, Forestry, and Fisheries, production of tencha in Japan has almost tripled, from 1,430 tons in 2012 to 4,176 tons in 2023.

Seeking World Heritage Listing for Ancient Japan’s Drink

Uji tea’s prestige can be attributed to the area’s unique environment and the devotion of locals to production techniques. This part of Japan was recognized long ago as an ideal place to cultivate tea. The Uji and Kizu rivers flow through the area, and it is blessed with a high annual rainfall. Its slightly elevated, sloped terrain has good water drainage and frequent fog, inhibiting frost that could damage tea sprouts.

Tea cultivation was first introduced to Kyoto during the Kamakura period (1185–1333), and during the subsequent Muromachi period (1333–1568) the shogunate encouraged the development of tea plantations, helping to build Uji tea’s first-class reputation. In the mid-Edo period (1603–1868), the Nihon sankai meibutsu zue (Illustrated Famous Products of the Mountains and Seas of Japan) explained the transmission of tea and the origins of Uji tea. It also described cultivation and harvesting in Uji and detailed the processing techniques, suggesting that Uji tea was already a widely recognized brand throughout Japan.

“Picking tea in Uji” from Nihon sankai meibutsu zue. (Courtesy National Diet Library digital collection)

Now, Uji tea refers to tea that is processed by Kyoto-based producers using traditional techniques, although the tea may be cultivated in Kyoto or one of three prefectures close to Uji: Nara, Shiga, or Mie. Japan’s Agency for Cultural Affairs has designated the tea culture of southern Kyoto Prefecture’s Yamashiro region as “Japan Heritage” in recognition of its importance to sadō​, itself a form of Japanese spirituality, and the region’s role in producing leading types of Japanese tea: powdered matcha, ordinary green leaf sencha, and the highest-quality gyokuro. Kyoto Prefecture is also leading an initiative to have the so-called “cultural landscape” of Uji’s tea registered as World Heritage.

Flavor Enhanced by Shade

In Uji, tea grown to produce tencha (which is dried and powdered as matcha) and the top-quality gyokuro is shaded for the final few weeks prior to harvesting to protect the leaves from intense sunlight. This prevents a key flavor component, theanine, from altering to produce catechins, which are bitter. The result is smoother-flavored tea. Tea cultivation under shade in Japan was described by Christian missionaries in the early seventeenth century, and the technique was transmitted to the West.

Tencha, tea grown in the shade of traditionally woven straw matting, for making matcha. (© Pixta)

Experiencing Tea and Its History

Visit the Tea and Uji Community Center Chazuna, close to Keihan Uji Station, to learn more about the history and cultural background of Uji tea. Chazuna has digital displays, areas to touch and experience tea, and a range of cultural experiences on offer, including decorating your own tea canister, harvesting the plant, and even grinding tea leaves to make matcha.

Chazuna features digital exhibits explaining the history of tea. (© Fujiwara Tomoyuki)

At Chazuna, you can try using a millstone to grind tencha. (© Fujiwara Tomoyuki)

The matcha-making experience, where visitors grind tea with a millstone, is popular with tourists, including families with children. After grinding the matcha, you can drink it alongside professionally ground tea to compare the difference. According to the center’s head, Sakayori Naohito, “When whisking tea, the key is to not be too forceful, to ensure it is mixed quickly, incorporating more air to produce a creamy texture.”

Other facilities in Uji have their own experiences on offer, including drinking different brands of tea to guess which is which, and opportunities to craft tea utensils.

There are even tea plantations in the center of Uji itself, and Chazuna has a terrace overlooking tea fields. Harvesting of sencha takes place in three stages from April through the summer months. But Uji’s tencha and gyokuro are harvested just once a year, and picking is still done by hand.

In the Muromachi period, the shōgun’s family and other powerful provincial lords (daimyō) owned tea plantations in Uji, collectively known as the “seven famous tea fields of Uji.” Of these, the only one which remains today is Okunoyama-en, in the Zenhō district of Uji.

Tea fields in Uji. The plants are grown under shading to avoid direct sunlight. (© Fujiwara Tomoyuki)

Traditional Techniques for More Aromatic Tea

Tencha is steamed in a special steamer, then heated and dried in a separate device. The dried leaves can then be ground by millstone to produce matcha. Gyokuro, meanwhile, is produced by harvesting young tea leaf buds grown under shade, which are then steamed and kneaded as they are dried.

Fukubun Seichajō, a tea factory in a residential district near Byōdōin, uses traditional cultivation and processing methods to produce tencha. It was founded in 1901, and still uses a century-old tencha drying machine, invented in Uji in 1924. The device uses heated tiles to dry the tea leaves with radiant heat, producing a distinctive aroma.

According to the factory’s fifth-generation owner Fukui Keiichi, they steam the young tea leaf buds for around 30 seconds, then dry them at around 200°C before separating the stalks from the leaves. “Our tile tencha drying machine is very special. It has been passed down since my great-grandfather’s days.”

Fukui Keiichi of Fukubun Seichajō explains how their historic factory uses heat and wind to produce full-flavored tencha from Uji-grown tea. (© Fujiwara Tomoyuki)

A Tea House Visited by Toyotomi Hideyoshi

Close to Uji Bridge is a tea house named Tsūen that looks as if it is right out of a period drama. Over 850 years ago, it played a role in guarding the bridge, while also serving tea to travelers passing through. It is mentioned in historical novels, and even in Japanese dictionaries.

Tsūen, near Uji Bridge, is Japan’s oldest tea house, tracing its history back to 1160. (© Fujiwara Tomoyuki)

The present building dates back to 1672. Inside, there is an array of tea urns on display dating back hundreds of years, and a wooden statue of Tsūen’s founder, received from the renowned Zen priest Ikkyū Sōjun (1394–1481). Records exist of visits to the tea house by such historic figures as shōgun Ashikaga Yoshimasa (1436–90), the warlord Toyotomi Hideyoshi (1537–98), and the shōgun Tokugawa Ieyasu (1543–1616).

Tsūen also stocks top-shelf matcha produced by the aforementioned Fukubun Seichajō. According to the shop’s manager, the twenty-fourth-generation owner Tsūen Yūsuke, the high-grade matcha is particularly popular among visitors from Japan and abroad alike.

Tsūen tea house, seen in the Ujigawa ryōgan ichiran (Sights on the Banks of the Uji River), printed in 1863. (Courtesy the National Diet Library digital collection)

In addition to selling various styles of Uji tea, they serve matcha-flavored sweets. There are benches outside where diners can try mildly bitter tea-flavored dumplings, matcha parfait, Uji azuki bean soft-serve ice cream, and other treats while enjoying views of the river and Uji Bridge.

Matcha served with dango dumplings at Tsūen tea house, Uji. (© Fujiwara Tomoyuki)

An Old Tea Wholesaler Becomes a Popular Shop

There are many specialist tea purveyors in Uji that trace their origins back for generations. Nakamura Tōkichi Main Store is a popular establishment dating back to 1854. Located on the high street leading to Uji Bridge, it is always buzzing with tourists.

Nakamura Tōkichi Main Store, close to JR Uji Station. The shop building was originally a tea wholesaler. (© Fujiwara Tomoyuki)

Nakamura Tōkichi Main Store offers a range of seasonal products and has a tasting corner. Visitors can compare the different colors, aromas and flavors of the teas for sale. (© Fujiwara Tomoyuki)

The store features striking white plastered walls and latticework, a typical style used by wholesalers in the Meiji era (1868–1912). In 2009, it was selected as a Cultural Landscape of Japan. Various teas are available for tasting in the former tea drying area of the wholesaler. The tea processing factory, built in the Taishō era (1912–26), has been refurbished as a café. Make a reservation to try your hand at grinding matcha, then imbibing it in the tea ceremony as either koi-cha (thick tea) or the thinner usu-cha.

The Nakamura Tōkichi Main Store café is inside a refurbished former tea processing factory. Its attractive garden is another delight. (© Fujiwara Tomoyuki)

The café has a central atrium in the ceiling, a legacy of the original tea processing factory, when it allowed heat from the processing to escape. The pillars still bear numbers jotted down by former employees, evoking images of the once busy workplace. The café’s most popular treat is its striking Maruto parfait. The dessert is served in a bamboo cylinder and contains matcha-flavored ice cream, chiffon cake, and jelly combined with other ingredients such as shiratama (rice flour dumplings) and raspberries. Another favorite is the namacha jelly, with a distinctive matcha taste and topped with ice cream, creating a taste (and texture) sensation. Nakamura Tōkichi operates another store and café close to Byōdōin.

Popular sweets at Nakamura Tōkichi Main Store include Maruto parfait (foreground) and namacha jelly. (© Matsumoto Sōichi)」

A Mind-boggling Variety of Matcha Foods

Walking through central Uji, you cannot help but notice the incredible array of matcha-flavored food and drink on offer. Matcha takoyaki (octopus balls), croquettes, beer . . . You could spend an entire day consuming the tea in wildly diverse forms.

According to locals, a traditional favorite souvenir is the dumplings called matcha dango. There are also unusual combinations, such as mitarashi dango, or skewered dumplings with a sweet soy glaze; dumplings​ topped with roasted kinako soy flour; matcha rusk cookies; matcha kintsuba (sweetened beans wrapped in dough)’ and fruit dipped in matcha chocolate.

An endless range of matcha-related souvenirs is available in Uji. (© Matsumoto Sōichi)

The Birthplace of Sencha Leaf Tea

Uji also has deep connections with sencha, the green tea most commonly consumed in Japan. Ōbakusan Manpukuji is a local temple established by Ingen (1592–1673), a Buddhist monk from China who introduced sencha culture to Japan. Baisaō (1675–1763), a Japanese monk from the temple, is considered to have helped popularize sencha tea culture and to have founded Senchadō, a sadō​ practice using sencha. Within the temple grounds stands Baisadō, a shrine built in Baisaō’s honor. The All Japan Senchadō Federation has its headquarters alongside the temple and holds an annual tea event here. In 2024, Japan’s Council for Cultural Affairs deemed that the temple buildings represent important culture introduced from Ming Dynasty China (1368–1644), and requested designation of its three main structures as National Treasures.

Baisadō, built in honor of the monk Baisaō, who trained at Manpukuji. (© Pixta)

(Originally published in Japanese. Research and text by Matsumoto Sōichi and Fujiwara Tomoyuki, Nippon.com. Banner photo: Enjoying matcha sweets at the Nakamura Tōkichi Main Store café, near JR Uji Station. The Council for the Promotion of the Ujicha Region has certified numerous Uji tea cafés in the city. © Fujiwara Tomoyuki.)