{"id":622310,"date":"2026-06-05T08:40:10","date_gmt":"2026-06-05T08:40:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/uk\/622310\/"},"modified":"2026-06-05T08:40:10","modified_gmt":"2026-06-05T08:40:10","slug":"the-overlooked-reason-youre-feeling-tired-all-the-time","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/uk\/622310\/","title":{"rendered":"The overlooked reason you\u2019re feeling tired all the time"},"content":{"rendered":"

This is\u00a0Everyday Science\u00a0with Clare Wilson, a subscriber-only newsletter from\u00a0The i Paper. If you\u2019d like to get this direct to your inbox every week,\u00a0you can sign up here<\/a>.<\/p>\n

Hello, and welcome back to Everyday Science.<\/p>\n

One of the most common medical symptoms that sends people to their doctors is persistent fatigue<\/a>. People report that they feel \u201ctired all the time\u201d so often that GPs give it the acronym TATT in patient notes.<\/p>\n

There are many potential causes, but now, a study has suggested that two possible explanations should be considered more often \u2013 deficiencies of two B vitamins<\/a>, called B12 and folate, also called B9.<\/p>\n

For various reasons, including some growing health conditions and the popularity of veganism<\/a>, it is becoming more common for people to be deficient in these vitamins. So, what are the signs and why are these nutrients so important?<\/p>\n

B12 and folate are important substances involved in a large group of metabolic processes, including making DNA \u2013 which means they are essential for tissue growth and repair \u2013 and making brain signalling chemicals involved in mood and motivation.<\/p>\n

If someone is persistently tired, the nutrient deficiency first suspected might be a lack of iron. Thanks to NHS awareness campaigns, people may have also heard of type 2 diabetes as a possible cause.<\/p>\n

But lack of B vitamins probably won\u2019t jump into most people\u2019s minds, said Dr Dan Baumgardt, an academic GP at the University of Bristol, who wasn\u2019t involved in the study. \u201cThese are nutrients the public are less familiar with,\u201d he said.<\/p>\n

There are many tests that doctors can do to investigate fatigue. \u201cPractically every single condition in the medical dictionary can cause tiredness in some form,\u201d said Dr Baumgardt. These include pregnancy, depression, carbon monoxide poisoning and chronic fatigue syndrome, also known as myalgic encephalomyelitis.<\/p>\n

The NHS guidelines body, Nice, recommends a range of tests and possible diagnoses<\/a> that GPs should consider. Blood tests for B12 and folate levels are on that list, but they are classed as \u201cadditional investigations\u201d. In other words, they are not in the first group of tests, points out Dr James Gill, a GP and lecturer at Warwick Medical School.<\/p>\n

And there\u2019s a hitch. Blood tests for B12 and folate levels aren\u2019t always correct on whether someone really is deficient, because levels in the blood may not reflect levels in the body\u2019s tissues.<\/p>\n

In fact, a different blood test, for a substance called homocysteine, may give a better picture. Homocysteine is involved in the same group of metabolic processes that use B12 and folate, and people who are deficient in the vital nutrients usually have high homocysteine in their blood.<\/p>\n

But often, GPs can\u2019t order homocysteine tests \u2013 they have to be requested by hospital doctors, which means they happen less often.<\/p>\n

Men and women show symptoms differently<\/p>\n

The latest study has highlighted these complexities. Researchers in Japan gave over 600 people questionnaires on their physical fatigue, what might be called mental fatigue, and how motivated they felt about doing activities.<\/p>\n

They also measured blood levels of vitamin B12, folate, and homocysteine. The results have been published in the journal, Nutrients<\/a>.<\/p>\n

The study showed that higher levels of homocysteine (indicating B12 or folate deficiency) were linked with worse fatigue in men and weaker mental motivation in women.<\/p>\n

But blood tests for B12 and folate showed only small correlations with fatigue and motivation, supporting the idea that they can be inaccurate. \u201cWe recommend measuring homocysteine concentrations,\u201d said Professor Hiroaki Kanouchi, at Osaka Metropolitan University, who led the research.<\/p>\n

The study does not prove the vitamin deficiencies were causing fatigue in these people, but does support the need for a trial of supplementation for persistent tiredness, he said.<\/p>\n

Gill said that if GPs suspect B vitamin deficiency even when blood tests are normal or borderline, they could still recommend treatment.<\/p>\n

Both vitamins can be taken as tablets, and an injection of B12 can also be given for a quick boost. \u201cIf a patient is very close to the border, let\u2019s just give you some more,\u201d he said.<\/p>\n

Mixed up with signs of ageing<\/p>\n

Other signs of B12 deficiency include mouth ulcers, pins and needles in the feet and memory problems or \u201cbrain fog\u201d.<\/p>\n

\u201cWhen people start to have reduced levels of B12, it\u2019s a very slow process,\u201d said Professor Martin Warren, a micronutrient researcher at the Quadram Institute. \u201cGradually, your energy levels drop, you become slightly more tired, you get a little bit of brain fog, all of these things creep up and you might think it\u2019s the ageing process.\u201d<\/p>\n

If someone suspects their B vitamin levels are at risk of being too low, they can tackle this with their diet.<\/p>\n

Good sources of B12 are all forms of meat, as well as foods that have been fortified with it, like some breakfast cereals and Marmite. Good sources of folate include beans, other pulses and green leafy vegetables.<\/p>\n

People who are at high risk of these deficiencies include vegans, as well as people with Crohn\u2019s disease, which reduces nutrient absorption, those taking a diabetes medicine called metformin and those taking drugs to reduce stomach acid called proton pump inhibitors.<\/p>\n

\u201cSome people soldier on but anybody who is feeling persistent tiredness should go and see their GP,\u201d said Baumgardt. \u201cIf it\u2019s a medical problem we might determine the cause.\u201d<\/p>\n

I\u2019ve also written<\/p>\n

Health guidelines now recommend strength training, as well as aerobic exercise like running, but how much should you do? The latest study suggests you should clock up at least 90 minutes a week<\/a>.<\/p>\n

I\u2019ve been watching<\/p>\n

I was pressured into seeing the new family movie, The Sheep Detectives at the weekend, and it was more fun than I expected. I\u2019m afraid it does feature talking sheep, but also has a stellar supporting cast of humans, with enjoyable turns from Hugh Jackman and Emma Thompson.<\/p>\n","protected":false},"excerpt":{"rendered":"This is\u00a0Everyday Science\u00a0with Clare Wilson, a subscriber-only newsletter from\u00a0The i Paper. If you\u2019d like to get this direct…\n","protected":false},"author":2,"featured_media":622311,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[17892,59,102,4016,56,54,55,6959],"class_list":["post-622310","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-fatigue","tag-gb","tag-health","tag-subscriber-newsletter","tag-uk","tag-united-kingdom","tag-unitedkingdom","tag-vitamins"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/622310","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=622310"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/622310\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/622311"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=622310"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=622310"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=622310"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}