Vitamin B12 Deficiency in Aging: Causes, Symptoms and Treatment

Vitamin B12 deficiency is a common but often overlooked issue in older adults, and it can have serious health consequences if left untreated. In this episode, Geriatrician Leslie Kernisan, MD MPH, explains why vitamin B12 is essential for nerve function, red blood cell production, and overall brain health.

Learn about the causes of B12 deficiency, including age-related changes, digestive issues, and conditions like pernicious anemia. Dr. Kernisan also discusses the subtle symptoms that may be missed in routine care, the importance of early testing, and how simple treatments can improve energy, memory, and well-being.

If you’re caring for an aging parent or want to maintain your own health as you age, this conversation provides practical, science-based insights on preventing, diagnosing, and treating vitamin B12 deficiency for better long-term outcomes.

Note: this video does NOT include paid promotion. Dr. K does mention the products she has personally used for herself, however she did not receive them for free, was not asked by any company to make this video, and was not paid for mentioning them as part of this educational video. Dr. K DOES have affiliate links for Amazon and Adapt Naturals, which means that if you choose to purchase through these links, Better Health While Aging will receive a small commission at no extra cost to you.

For the vitamins Dr. K recommended in the video, you can get them here:

These are affiliate links, so any purchases will help support Better Health While Aging, thank you!

Chapters:

00:00 Introduction to Vitamin B12 Deficiency
03:01 What is Vitamin B12?
07:12 Common Causes of Vitamin B12 Deficiency in Older Adults
09:24 Symptoms of Vitamin B12 Deficiency
11:59 Pernicious Anemia and Its Relation to B12 Deficiency
13:45 Why Vitamin B12 Deficiency is Often Missed
16:18 Who Should Be Checked for Vitamin B12 Deficiency?
17:12 Testing for Vitamin B12 Deficiency
20:42 Treatment Options for Vitamin B12 Deficiency
24:22 Preventing Vitamin B12 Deficiency
27:53 Recap and Key Takeaways

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[NutritionForHealth]

This is such an important topic! So many people focus on calcium and vitamin D, but B12 is just as crucial for brain and nerve health. Really appreciate this deep dive!

[philboydstudge]

Thank you for this video, I hope it saves others from the hell I went through. I'm 70 years old and eat a vegan diet. Over the last 10 years I've suffered from peripheral neuropathy that had been getting steadily worse. The miserable excuse for a "primary physician" (actually an overworked poorly trained PA) I was seeing had no clue what was going on. I underwent a tedious and painful diagnostic test that showed, wait for it, that I had peripheral neuropathy. Frustrated and desperate, I did some of my own research and learned that a B12 deficiency was a possible cause, especially so given my diet. I started taking a daily B12 supplement hoping for the best but not expecting much. After 2 months I started to see some improvement. The numbness and tingling in my feet and hands started to subside. The tremors that had been keeping me from practicing my hobbies began to subside. After 6 months my symptoms are all be gone. When I told my "primary" all I got was condescension. Needless to say I fired her and found another, better practice.

[lopezjulian]

It’s crazy how nobody is talking about Rethinking Health Secrets! This book made me question so much when it comes to health, it has some serious knowledge

[maretabester]

Years ago I had to take my mother to a geriatric doctor. As he was chatting to her, he turned to me and said I should always take vit B12. She was in her 80's and I in my late 50's. Since then I've been taking it regularly.
Thank you for a very informative video. 🌸💕

[rawbacon]

Tired and don't feel like writing an in depth comment. I'll just say I added a B-12 to my Grandmother's daily routine and it took away her Dementia symptoms. Her mind was still fine when she died at 90.

[NickMasseyRideon]

I have just turned 65, been active my whole life, but life seems to be catching up with me, the past year has been horrible for my health. I just subscribed in the hope that this channel can help me and be a part of my "getting healthy" again protocol

[edwardlulofs]

I had nerve damage after a leg injury.
A common idea is that nerve function doesn’t return. But I have read some interesting anecdotal stories about some recovery. So I took up swimming every day. After 1 and 1/2 years of swimming, I do seem to have improvement.
Any exercise helps, but since I couldn’t walk, I am swimming.
My MD has no geriatric training so I am really thankful for your channel. 😊

[bmackillop]

Very helpful.Recently diagnosed with low Vitamin B12(4 weeks).My symptom was FATIGUE with mild depression.Starting to feel a bit better.Repeat bold work in one month

[GeneAnderson-wybu]

I really enjoy your coverage, I’m 84 and my attention span doesn’t allow too much info at once, attention span is too short. Thankfully I can go back and listen.

[joyceshaw]

Ended up my career, on disability, due to pernicious anemia lacking B12 absorption. Missed by Dr, s for years. Memory so poor I seemed to be having OCD rechecking my work and then not remembering the info I re-checked. Had all the other symptoms mentioned here. I re-couped a bit of my health with treatment, but far from being able to function in life. Permanent damage now, I have concerns in my managing changes that come up and just live with it. Please if you even question the possibility, get your levels checked, re-check in 2 year if you remain the same or get worse .
Disability is not fun… Lower monthly payments than social security, especially after giving work hours to others for 2 or 3 years due to exhaustion, mental slowdowns.

[lyndaturner]

I’ve known about B12 deficiency for years as I suffer from nerve pain, I used to take a B complex, but recently I’ve been taking just B12 and I’ve noticed a huge difference, I was getting pain in my toes and various other pains in my body but after a few weeks I’ve noticed a massive improvement, , I’m not vegan but don’t eat much meat more fish, I’m 76 and I am very fit and active and even though I have arthritis in hips knees and hands it doesn’t hold me back, I walk garden do housework and feel I have more energy than I had before. So thanks for reinforcing the benefits of this vitamin

[AnneStevens-dndi]

Your program has really helped me. I have started to take B12, and have already seem some improvmenrs. Been taking it for about 10 days, and I sleeping much better. Other issues are showing slight improvement all ready. Looking forward to seeing what the future brings. I am 86 and wish I had found out about B12 sooner!

[Bmarker]

Dear Dr. Kernisan, Thank you for responding to my comment. After reading your response, I apologize for my hasty judgment of you. I value your channel and look forward to your videos.I deleted my previous thoughtless comment

[HealthHaven]

This video is an absolute eye-opener on the importance of vitamin B12, especially for older adults. The detailed explanation of causes, symptoms, and treatments makes it easy to understand why this deficiency is often overlooked. I appreciate the emphasis on early detection and prevention—truly life-changing information. Thank you, Dr. Kernison! 👏👏

[leveneziadvm]

Lots of good information Doc. As a veterinarian, it's routine to administer cobalamin and folate in chronic GI disease and to check levels of each to differentiate small bowel from large bowel disease. As an "old guy" I was diagnosed with borderline anemia and low B-12 which was quickly remedied by taking oral 1000mcg of B-12 . Keep up the quality information

[mariepetersen]

Doctor Kernisan . I thank God that today, Sunday 02/22/25 ..I happened to discover your podcast regarding vitamin B12 Deficincy. I have been through breast cancer chemotherapy radiation..later coma and life support for 6 months out 8 months from complications of ovarian cancer surgery..later diagnosed with Carcinoma that had spread just had surgery few months ago at Baylor Hospital Dallas Texas although I live in Vancouver Washington.( My daughter works in the medical field in Dallas) My point for sharing all this with you.. I know your podcast, and the way you explain so intellectually about this issue of vitamin b12 deficiency it is going to help many people. I have been getting the b12 injection monthly for several years. I now have Crohns Disease, and I don't know what I would do without the help from God, and the vitamin b12, and the way I take care of myself and the foods i prepare and eat.
One of the comments I read regarding your B12 Podcast someone said, " Why not just talk about the foods to eat without vitamin supplements?" I just want to say.. I myself eat organic no MSG. Gluten free etc prepare my own meals no can no box foods etc organic chicken Pastured raised eggs etc take vit C -E etc and my body still needs the B12 vitimin.
An abundance of BLESSINGS upon you🙏

[edwardlulofs]

I’m a senior and I find this channel very useful. I subscribed and watch all of your videos.
Thank you 😊

[wakabuilder]

Great video really helpful make more Doc tor please, I am 88 and want to stay with my 76-year-old wife to love her.

[Thehealthyhabit]

"I was really surprised to learn that a lack of vitamin B12 can have such serious effects on the nervous system! This is especially important for older adults. Thanks for sharing such valuable information!"

[JScox]

Methylcobalamin is the correct form of B-12. It is better absorbed by humans than any other form. I started out at 2, 000 mcg daily & was recently able to drop back to 1, 000 mcg daily just for maintenance. When I first added it, the change was incredible, most notably in energy. I'm 72, no more napping for me these days!