{"id":8191,"date":"2026-10-13T15:44:00","date_gmt":"2026-10-13T15:44:00","guid":{"rendered":"https:\/\/bioprofile.com\/?p=8191"},"modified":"2026-10-13T19:33:13","modified_gmt":"2026-10-13T19:33:13","slug":"vitamin-b12-deficiency-symptoms","status":"publish","type":"post","link":"https:\/\/bioprofile.com\/en\/vitamin-b12-deficiency-symptoms\/","title":{"rendered":"Vitamin B12 deficiency symptoms: what you notice, who is more at risk and when to see your GP"},"content":{"rendered":"\n<article class=\"wp-block-group bp-blog is-layout-flow wp-block-group-is-layout-flow\">\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n<link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin>\n<link rel=\"stylesheet\" href=\"https:\/\/fonts.googleapis.com\/css2?family=Poppins:wght@300;400;500;600;700&#038;display=swap\">\n<style id=\"bp-blog-design\">\n.bp-blog {\n  --bp-ink: #212527; --bp-teal: #005859; --bp-teal-deep: #006B62; --bp-emerald: #228A62;\n  --bp-green: #7CA74D; --bp-lime: #B7CB33; --bp-lime-soft: #B7CB3329; --bp-green-aa: #4F6B28;\n  --bp-beige: #EDEAE5; --bp-sand: #DBD4CB; --bp-pale-teal: #D9E6E6; --bp-white: #FFFFFF;\n  --bp-foot: #6b6b6b;\n  --bp-font: 'Poppins','Segoe UI',Arial,sans-serif;\n  --bp-fs-h1: 40px; --bp-fs-h2: 29px; --bp-fs-h3: 21px; --bp-fs-body: 17px;\n  --bp-fs-lead: 19px; --bp-fs-small: 14px; --bp-fs-foot: 13px; --bp-fs-btn: 17px;\n  --bp-lh-body: 1.75;\n  --bp-s-2: 8px; --bp-s-3: 12px; --bp-s-4: 16px; --bp-s-5: 24px; --bp-s-6: 32px;\n  --bp-s-7: 44px; --bp-s-8: 72px;\n  --bp-measure: 875px; --bp-prose: 875px; --bp-side: 40px; --bp-portrait: 132px;\n  --bp-radius-card: 20px; --bp-radius-btn: 10px; --bp-radius-chip: 999px;\n  --bp-shadow: 0 10px 30px rgba(0,88,89,0.10); --bp-shadow-soft: 0 2px 10px rgba(0,88,89,0.06);\n  font-family: var(--bp-font); font-size: var(--bp-fs-body); line-height: var(--bp-lh-body);\n  color: var(--bp-ink); background: var(--bp-white); -webkit-font-smoothing: antialiased;\n}\n.bp-blog, .bp-blog * { box-sizing: border-box; }\n.bp-blog p, .bp-blog li, .bp-blog h1, .bp-blog h2, .bp-blog h3, .bp-blog a, .bp-blog td,\n.bp-blog th, .bp-blog cite { overflow-wrap: break-word; min-width: 0; }\n.bp-blog h1, .bp-blog h2, .bp-blog h3 { text-wrap: balance; }\n.bp-blog p, .bp-blog li { text-wrap: pretty; }\n\/* WordPress core's flow layout puts 24px above every child after the first; inside\n   a grid or a flex row that is a misalignment (measured on the scan pages 2026-08-21) *\/\n.bp-blog .bp-blog-author > *, .bp-blog .bp-blog-related > *, .bp-blog .bp-blog-verify > * { margin-block: 0; }\n\n\/* --- sections: one column, the article measure, the section rhythm ------------ *\/\n.bp-blog-sec { position: relative; background: var(--bp-white); margin-block: 0;\n  padding-block: var(--bp-s-7);\n  padding-inline: max(var(--bp-side), calc((100% - var(--bp-measure)) \/ 2)); }\n.bp-blog-sec > *:last-child { margin-block-end: 0; }\n.bp-blog-sec > p, .bp-blog-sec > ul, .bp-blog-sec > ol, .bp-blog-sec > .wp-block-quote,\n.bp-blog-sec > .bp-blog-faq-item, .bp-blog-sec > .bp-blog-takeaways, .bp-blog-sec > .bp-blog-toc,\n.bp-blog-sec > .bp-blog-refs, .bp-blog-sec > .bp-blog-srclead { max-width: var(--bp-prose); }\n.bp-blog-sec--head { padding-block: var(--bp-s-7) 0; }\n.bp-blog-sec--body { padding-block: var(--bp-s-6) var(--bp-s-7); }\n.bp-blog-sec--beige { background: var(--bp-beige); }\n.bp-blog-sec--wash { background: linear-gradient(180deg, #B7CB331A 0%, #B7CB330D 100%), #FFFFFF; }\n.bp-blog-sec--tight { padding-block: var(--bp-s-6); }\n\/* A COLOURED SECTION IS A PANEL, so it carries the panel radius. Measured on the\n   live site 2026-08-28 rather than chosen: bioprofile.com's own coloured blocks\n   come in two families, full-bleed strips (w=1440 edge to edge, radius 0, 40px\n   side padding) and inset panels (the lime block w=677 and the sand block w=576,\n   both radius 16px). Ours cannot be the first: the theme's content wrapper is\n   1140px, so a coloured section here stops 150px short of the screen on both\n   sides and reads as an inset panel with square corners, which is the thing the\n   operator saw. So it takes the panel treatment. 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}\n}\n\n\/* --- verified by: exists only for a real, confirmed verifier ------------------- *\/\n.bp-blog .bp-blog-verify { background: var(--bp-white); border: 1px solid var(--bp-sand);\n  border-radius: var(--bp-radius-card); box-shadow: inset 5px 0 0 var(--bp-lime), var(--bp-shadow-soft);\n  padding: var(--bp-s-4) var(--bp-s-5) var(--bp-s-4) var(--bp-s-6); margin-block: 0 var(--bp-s-4); }\n.bp-blog .bp-blog-verify > * { margin-block: 0 var(--bp-s-2); max-width: none; }\n.bp-blog .bp-blog-verify-name { font-size: 18px; font-weight: 700; }\n.bp-blog .bp-blog-verify-cred { font-size: var(--bp-fs-small); color: var(--bp-foot); }\n\/* T332, Jesse 2026-09-17: a SMALL box at the top, under the introduction *\/\n.bp-blog .bp-blog-verify--top { display: grid; grid-template-columns: 56px 1fr; column-gap: 14px;\n  align-items: center; padding: 12px 16px; margin-block: var(--bp-s-3); max-width: var(--bp-prose); }\n.bp-blog .bp-blog-verify--top > * { margin: 0; }\n.bp-blog .bp-blog-verify--top .wp-block-image { grid-row: span 3; 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Per portie noemt het Voedingscentrum zalm (100 gram) met 4,0 microgram, ruim meer dan de 2,8 microgram die volwassenen per dag nodig hebben. Rundvlees, eieren, melk en yoghurt bevatten minder.\"\n          }\n        },\n        {\n          \"@type\": \"Question\",\n          \"name\": \"Kun je zelf met B12 beginnen?\",\n          \"acceptedAnswer\": {\n            \"@type\": \"Answer\",\n            \"text\": \"De meeste mensen hebben geen supplement nodig. Veganisten zijn de uitzondering en krijgen het advies er een te nemen. Heb je klachten, dan adviseert Thuisarts om eerst contact op te nemen met je huisarts. Dat meer ook beter is, is niet bewezen: in een Nederlands cohort overleden mensen met hogere B12-waarden in het bloed iets vaker. 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That matters, because some groups are clearly more at risk.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup> <a href=\"https:\/\/bioprofile.com\/en\/scan-lifestyle-test\/\">BioProfile's lifestyle scan<\/a> gives you an indication of where you stand today in how you live and age. This is not a diagnosis. It is insight, to see where you stand today and to help you make better choices in your diet and lifestyle. The scan does not measure your B12 level and does not identify a cause. Only a doctor can assess that.<\/p>\n\n\n\n<div class=\"wp-block-group bp-blog-verify bp-blog-verify--top is-layout-flow wp-block-group-is-layout-flow\">\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"1000\" src=\"https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/09\/rt-portret-justinas-slikas.webp\" alt=\"Portrait of Justinas \u0160likas\" class=\"wp-image-5796\" srcset=\"https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/09\/rt-portret-justinas-slikas.webp 800w, https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/09\/rt-portret-justinas-slikas-240x300.webp 240w, https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/09\/rt-portret-justinas-slikas-768x960.webp 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p class=\"bp-blog-verify-name wp-block-paragraph\">Verified by <a href=\"https:\/\/bioprofile.com\/experts\/justinas-slikas\/\">Justinas \u0160likas, PhD<\/a><\/p>\n\n\n\n<p class=\"bp-blog-verify-cred wp-block-paragraph\">PhD in chemistry from the University of Edinburgh<\/p>\n\n\n\n<p class=\"bp-blog-verify-date wp-block-paragraph\">Checked on 4 October 2026<\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-takeaways is-layout-flow wp-block-group-is-layout-flow\">\n\n<h2 class=\"wp-block-heading\">In short<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Vitamin B12 deficiency symptoms fall into two groups: nerve symptoms such as tingling in your hands and feet, and the tiredness, shortness of breath and dizziness that come with anaemia.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup><\/li>\n\n\n<li>The most common cause of a severe deficiency is a stomach condition seen mainly in older people. Long-term use of metformin or acid reflux medication is also linked to lower B12.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">2<\/a>,<a href=\"#bronnen\">3<\/a>,<a href=\"#bronnen\">4<\/a><\/sup><\/li>\n\n\n<li>The lifestyle scan gives you self-insight into how you live and age. The scan does not measure your B12 level and is not a diagnosis.<\/li>\n\n<\/ul>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-toc is-layout-flow wp-block-group-is-layout-flow\">\n\n<p class=\"bp-blog-toclabel wp-block-paragraph\">Contents<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n\n<li><a href=\"#vitamine-b12-tekort-symptomen-wat-je-merkt\">Vitamin B12 deficiency symptoms: what you notice<\/a><\/li>\n\n\n<li><a href=\"#wie-loopt-meer-risico\">Who is more at risk<\/a><\/li>\n\n\n<li><a href=\"#symptomen-tekort-vitamine-b12-wanneer-naar-de-huisarts\">Vitamin B12 deficiency symptoms: when to see your GP<\/a><\/li>\n\n\n<li><a href=\"#waar-vitamine-b12-in-zit-en-hoeveel-je-nodig-hebt\">Where vitamin B12 is found and how much you need<\/a><\/li>\n\n\n<li><a href=\"#tabletten-injecties-en-zelf-b12-nemen\">Tablets, injections and taking B12 yourself<\/a><\/li>\n\n\n<li><a href=\"#wat-de-leefstijlscan-meet-en-wat-niet\">What the lifestyle scan measures and what it doesn't<\/a><\/li>\n\n\n<li><a href=\"#samengevat\">In summary<\/a><\/li>\n\n\n<li><a href=\"#veelgestelde-vragen\">Frequently asked questions<\/a><\/li>\n\n<\/ol>\n\n<\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"vitamine-b12-tekort-symptomen-wat-je-merkt\">Vitamin B12 deficiency symptoms: what you notice<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Thuisarts describes two groups of symptoms. The first group is nerve symptoms: tingling in your hands and feet, reduced feeling in your fingers, the feeling of walking on cotton wool and problems with your balance. The second group is the symptoms of anaemia: feeling tired and weak, getting short of breath during exertion, dizziness, a fast heartbeat, headache and ringing in your ears.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup> In a clinical review article, tingling or numbness on both sides of the body and problems with walking were the most common nerve symptoms.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">2<\/a><\/sup><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In short: vitamin B12 deficiency symptoms can show up in your nerves, in your energy or in both. Tiredness on its own has many possible causes, but tingling in both feet is a more specific sign.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"wie-loopt-meer-risico\">Who is at greater risk<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The most common cause of a severe deficiency is autoimmune gastritis, also known as pernicious anaemia: the body attacks the stomach lining, and B12 is no longer absorbed. In large case series, the median age of the people affected was 70 to 80 years. A milder form of thinning stomach lining, in which the B12 in food does not come loose from its protein, occurs in up to 20 per cent of older people.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">2<\/a><\/sup><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So age plays a part on its own: an older stomach can release less B12 from food, even from a good diet. It is one of the quieter changes that come with the years. You can read what else shifts in <a href=\"https:\/\/bioprofile.com\/en\/healthy-ageing-what-changes-with-the-years\/\">what changes as you get older<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Thuisarts also names these groups: people who eat only plant-based food without products with added B12 or a supplement, people with stomach or bowel conditions such as Crohn's disease and ulcerative colitis, people who drink a lot of alcohol every day and eat poorly, people who take omeprazole or metformin, and people who regularly use nitrous oxide.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Two medicines have been studied well. In a Dutch study of 390 people with type 2 diabetes who were followed for just over four years, B12 levels at the end were about a fifth lower with metformin than with a placebo. About 7 extra people in every 100 developed a deficiency.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">3<\/a><\/sup> In a large American study, people with a B12 deficiency had more often taken a stomach acid reducer for two years or longer (12 per cent versus 7 per cent). The link was clearly stronger at higher doses.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">4<\/a><\/sup><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">What this means for you: if you have been taking one of these medicines for years and you notice the symptoms above, that is something to discuss with your GP. Do not stop a medicine on your own.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Among people who eat plant-based, a review of 40 studies in vegetarian adults found that between 0 and 86.5 per cent had a deficiency, and vegans who took no supplement ran a particularly high risk.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">5<\/a><\/sup> Put simply: if you eat a fully plant-based diet without getting B12 from fortified foods or a supplement, you will probably end up with a deficiency.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"symptomen-tekort-vitamine-b12-wanneer-naar-de-huisarts\">Vitamin B12 deficiency symptoms: when to see your GP<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Thuisarts advises contacting your GP if you have signs of anaemia, if you have nerve symptoms such as reduced feeling or tingling in your fingers, if you eat a fully plant-based diet and have symptoms that fit with it, or if you have symptoms while taking stomach acid reducers such as omeprazole, or metformin.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup><\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"waar-vitamine-b12-in-zit-en-hoeveel-je-nodig-hebt\">Where vitamin B12 is found and how much you need<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Adults need 2.8 micrograms of vitamin B12 a day. B12 is found in animal products. Per portion, the Voedingscentrum lists salmon (100 grams) with 4.0 micrograms, beef (75 grams) with 1.6, an egg with 0.8, a glass of milk (150 ml) with 0.7 and yoghurt (150 ml) with 0.6. Vegans are advised to use products with added B12 and a supplement that matches the daily amount. Most other people do not need a supplement.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">6<\/a><\/sup><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A Dutch study in older people found that the blood markers for B12 improved as intake rose, but levelled off above an intake of about 5 micrograms a day.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">7<\/a><\/sup> This means a varied diet with some animal products covers most of what you need. Above that point, eating more made little difference to blood levels.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"tabletten-injecties-en-zelf-b12-nemen\">Tablets, injections and taking B12 yourself<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If a deficiency is found, Thuisarts mentions tablets of 1,000 micrograms (1 milligram) a day for 3 months.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup> High-dose tablets work about as well as monthly injections to bring blood levels and nerve findings back to normal.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">2<\/a><\/sup> A Cochrane review of three small studies found no meaningful difference in blood levels between tablets and injections. The evidence was of low quality, and tablets cost less.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">8<\/a><\/sup><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">There is no proof that more is better. In a Dutch cohort of 5,571 adults followed for about eight years, the people with the highest B12 levels died about twice as often as the people with the lowest levels. After the researchers took other factors into account, a higher level was still linked to a slightly higher risk. The researchers write that the reason is unknown, and the study does not show that B12 itself causes harm.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">9<\/a><\/sup> For you, this means that taking B12 without a reason is not a free extra. If you have symptoms, talking to your GP comes first.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"wat-de-leefstijlscan-meet-en-wat-niet\">What the lifestyle scan measures and what it does not<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The lifestyle scan looks at how you live and age, and gives you a starting point to compare against later. The scan does not read a B12 level, and tingling or tiredness can have many causes that the scan does not show. The scan is not a diagnosis. If you want to know what lifestyle has to do with the pace at which you age, <a href=\"https:\/\/bioprofile.com\/en\/biological-age-versus-calendar-age\/\">biological age versus calendar age<\/a> explains the difference.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"samengevat\">In summary<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Symptoms of vitamin B12 deficiency include nerve problems, and the tiredness and shortness of breath that come with anaemia. Older people, plant-based eaters without B12, people with stomach or bowel conditions and long-term users of metformin or acid reflux medication are more at risk. Animal products provide your B12. Most people get enough, but vegans need a supplement. If you have symptoms, your GP is the place to go. The lifestyle scan gives you insight into how you live and age.<\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-sec bp-blog-cta is-layout-flow wp-block-group-is-layout-flow\">\n\n<h2 class=\"wp-block-heading\">See where you stand<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The lifestyle scan gives you a starting point for how you live and age. What the scan measures and what it is based on is set out on the scan page.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/bioprofile.com\/en\/scan-lifestyle-test\/\">Start the lifestyle scan<\/a><\/div>\n\n<\/div>\n\n\n\n<p class=\"bp-blog-ctamicro wp-block-paragraph\">Free, about 3 minutes. An analysis of your answers, never a diagnosis. <a href=\"https:\/\/bioprofile.com\/en\/free-health-check-tests\/\">All health scans<\/a><\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-sec bp-blog-sec--wash is-layout-flow wp-block-group-is-layout-flow\">\n\n<h2 class=\"wp-block-heading\" id=\"veelgestelde-vragen\">Frequently asked questions<\/h2>\n\n\n\n<div class=\"wp-block-group bp-blog-faq-item is-layout-flow wp-block-group-is-layout-flow\">\n\n<h3 class=\"wp-block-heading\">How do I raise my B12 quickly?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Whether you have a deficiency is for a GP to judge. Thuisarts mentions tablets of 1,000 micrograms a day for 3 months.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup> A Cochrane review found that tablets at that dose raised blood levels about as well as injections, although the evidence was of low quality.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">8<\/a><\/sup><\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-faq-item is-layout-flow wp-block-group-is-layout-flow\">\n\n<h3 class=\"wp-block-heading\">Which disease causes a B12 deficiency?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The most common cause of a severe deficiency is autoimmune gastritis, also known as pernicious anaemia.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">2<\/a><\/sup> Bowel conditions such as Crohn's disease and ulcerative colitis also raise the risk.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup><\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-faq-item is-layout-flow wp-block-group-is-layout-flow\">\n\n<h3 class=\"wp-block-heading\">What contains the most vitamin B12?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In animal products. Per portion, the Voedingscentrum lists salmon (100 grams) at 4.0 micrograms, well above the 2.8 micrograms adults need a day. Beef, eggs, milk and yoghurt contain less.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">6<\/a><\/sup><\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-faq-item is-layout-flow wp-block-group-is-layout-flow\">\n\n<h3 class=\"wp-block-heading\">Can you start taking B12 yourself?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Most people do not need a supplement. Vegans are the exception and are advised to take one.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">6<\/a><\/sup> If you have symptoms, Thuisarts advises contacting your GP first.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">1<\/a><\/sup> There is no proof that more is better: in a Dutch cohort, people with higher B12 levels in their blood died slightly more often. The researchers cannot say why.\u2060<sup class=\"bp-blog-sup\"><a href=\"#bronnen\">9<\/a><\/sup><\/p>\n\n<\/div>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-sec bp-blog-sec--beige bp-blog-sec--tight is-layout-flow wp-block-group-is-layout-flow\">\n\n<h2 class=\"wp-block-heading\" id=\"bronnen\">Sources<\/h2>\n\n\n\n<p class=\"bp-blog-srclead wp-block-paragraph\">Every source below was checked on the day this article was published. The numbering follows the text.<\/p>\n\n\n\n<ol class=\"wp-block-list bp-blog-refs\">\n\n<li>NHG. Ik heb misschien te weinig vitamine B12. Thuisarts.nl. <a href=\"https:\/\/www.thuisarts.nl\/vitamine-b12\/ik-heb-misschien-te-weinig-vitamine-b12\">thuisarts.nl<\/a><\/li>\n\n\n<li>Stabler SP. Clinical practice. Vitamin B12 deficiency. New England Journal of Medicine, 2013;368:149-160. <a href=\"https:\/\/doi.org\/10.1056\/NEJMcp1113996\">doi.org\/10.1056\/NEJMcp1113996<\/a><\/li>\n\n\n<li>de Jager J, Kooy A, Lehert P, et al. Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial. BMJ, 2010. Mean B12 19% lower with metformin than with placebo (95% CI -24% to -14%; P&lt;0.001); risk of deficiency 7.2 percentage points higher (number needed to harm 13.8 per 4.3 years). <a href=\"https:\/\/doi.org\/10.1136\/bmj.c2181\">doi.org\/10.1136\/bmj.c2181<\/a><\/li>\n\n\n<li>Lam JR, Schneider JL, Zhao W, Corley DA. Proton pump inhibitor and histamine 2 receptor antagonist use and vitamin B12 deficiency. JAMA, 2013. Two years or more of a proton pump inhibitor: OR 1.65 (95% CI 1.58 to 1.73); more than 1.5 pills a day: OR 1.95 (95% CI 1.77 to 2.15). <a href=\"https:\/\/doi.org\/10.1001\/jama.2013.280490\">doi.org\/10.1001\/jama.2013.280490<\/a><\/li>\n\n\n<li>Pawlak R, Lester SE, Babatunde T. The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. European Journal of Clinical Nutrition, 2014. <a href=\"https:\/\/doi.org\/10.1038\/ejcn.2014.46\">doi.org\/10.1038\/ejcn.2014.46<\/a><\/li>\n\n\n<li>Voedingscentrum. Vitamine B12. Encyclopedie, voedingscentrum.nl. <a href=\"https:\/\/www.voedingscentrum.nl\/encyclopedie\/vitamine-b12.aspx\">voedingscentrum.nl<\/a><\/li>\n\n\n<li>van Wijngaarden JP, Dhonukshe-Rutten RAM, Brouwer-Brolsma EM, et al. Vitamin B12 intake and related biomarkers: associations in a Dutch elderly population. Journal of Nutrition, Health and Aging, 2017. <a href=\"https:\/\/doi.org\/10.1007\/s12603-017-0911-6\">doi.org\/10.1007\/s12603-017-0911-6<\/a><\/li>\n\n\n<li>Wang H, Li L, Qin LL, Song Y, Vidal-Alaball J, Liu TH. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Cochrane Database of Systematic Reviews, 2018. <a href=\"https:\/\/doi.org\/10.1002\/14651858.CD004655.pub3\">doi.org\/10.1002\/14651858.CD004655.pub3<\/a><\/li>\n\n\n<li>Flores-Guerrero JL, Minovic I, Groothof D, et al. Association of plasma concentration of vitamin B12 with all-cause mortality in the general population in the Netherlands. JAMA Network Open, 2020. After adjustment, HR per 1-SD increase in B12 1.25 (95% CI 1.06 to 1.47; P = .006). <a href=\"https:\/\/doi.org\/10.1001\/jamanetworkopen.2019.19274\">doi.org\/10.1001\/jamanetworkopen.2019.19274<\/a><\/li>\n\n<\/ol>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-sec bp-blog-sec--tight is-layout-flow wp-block-group-is-layout-flow\">\n\n<h2 class=\"wp-block-heading\">Also read<\/h2>\n\n\n\n<div class=\"wp-block-group bp-blog-related is-layout-flow wp-block-group-is-layout-flow\">\n\n<div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\">\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/bioprofile.com\/en\/healthy-ageing-what-changes-with-the-years\/\">Healthy ageing: what measurably changes over the years, what a 30-year Dutch cohort puts at the top and what a lifestyle scan measures<\/a><\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\">\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/bioprofile.com\/en\/biological-age-versus-calendar-age\/\">Biological age versus calendar age: what biological age tests measure, what the numbers are linked to and what a lifestyle scan shows<\/a><\/p>\n\n<\/div>\n\n<\/div>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-sec bp-blog-sec--tight is-layout-flow wp-block-group-is-layout-flow\">\n\n<h2 class=\"wp-block-heading\">Written by<\/h2>\n\n\n\n<div class=\"wp-block-group bp-blog-author is-layout-flow wp-block-group-is-layout-flow\">\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"320\" height=\"320\" src=\"https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/07\/author-jesse-round-320.jpg\" alt=\"Jesse van der Velde\" class=\"wp-image-4815\" srcset=\"https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/07\/author-jesse-round-320.jpg 320w, https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/07\/author-jesse-round-320-300x300.jpg 300w, https:\/\/bioprofile.com\/wp-content\/uploads\/2026\/07\/author-jesse-round-320-150x150.jpg 150w\" sizes=\"(max-width: 320px) 100vw, 320px\" \/><\/figure>\n\n\n\n<div class=\"wp-block-group bp-blog-authorid is-layout-flow wp-block-group-is-layout-flow\">\n\n<p class=\"bp-blog-authorrole wp-block-paragraph\">Founder of BioProfile<\/p>\n\n\n\n<p class=\"bp-blog-authorname wp-block-paragraph\">Jesse van der Velde<\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-authorbody is-layout-flow wp-block-group-is-layout-flow\">\n\n<p class=\"bp-blog-authorbio wp-block-paragraph\">Jesse van der Velde has been guiding people to a new body and optimal health since 2006, and has written or co-written fifteen books on nutrition and health. Forever Young (2012) and Superfood Recipes (2013) both reached number 1 in the Netherlands.<\/p>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-authormeta is-layout-flow wp-block-group-is-layout-flow\">\n\n<p class=\"bp-blog-authorbio wp-block-paragraph\"><a href=\"https:\/\/nl.linkedin.com\/in\/jessevdv\">LinkedIn<\/a><\/p>\n\n\n\n<p class=\"bp-blog-dates wp-block-paragraph\">Published on 13 October 2026 \u00b7 Last updated on 13 October 2026<\/p>\n\n<\/div>\n\n<\/div>\n\n<\/div>\n\n\n\n<div class=\"wp-block-group bp-blog-sec bp-blog-sec--foot is-layout-flow wp-block-group-is-layout-flow\">\n\n<p class=\"bp-blog-legal wp-block-paragraph\">BioProfile analyses your health status to guide you and your coach. It does not make a diagnosis, only a doctor can do that. Built on validated health questionnaires; the combined BioProfile score is not itself a validated clinical instrument yet. Your answers stay private (GDPR).<\/p>\n\n<\/div>\n\n<\/article>\n","protected":false},"excerpt":{"rendered":"<p>Tingling feet, tiredness, shortness of breath: vitamin B12 deficiency symptoms, who is more at risk, where B12 is found and when to see your GP.<\/p>\n","protected":false},"author":18,"featured_media":7785,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_yoast_wpseo_meta-robots-noindex":"2","_yoast_wpseo_opengraph-image":"","_yoast_wpseo_opengraph-image-id":"","_yoast_wpseo_twitter-image":"","_yoast_wpseo_twitter-image-id":"","inline_featured_image":false,"footnotes":""},"categories":[71],"tags":[],"class_list":["post-8191","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-healthy-aging-en"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Vitamin B12 deficiency symptoms: what to look 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