vitamin B12
Have you ever wondered if depression could be eased with an inexpensive over-the-counter supplement, no prescription required? Or how about extinguishing your chronic anxiety through more consumption of certain foods that contain natural stress-reducing ingredients? Read on, because I've got something for you that will both surprise and delight.

Every day I see patients who want to do everything in their power to avoid mind-altering pharmaceutical drugs. This is especially true of women hoping to become pregnant or who already are. Among the tests I order to get a sense of my patients' biology when they first come see me, one of the results I like to review immediately is their level of vitamin B12. Is it low? If so, could it be the reason they are in my office to begin with?

Vitamin B12 deficiency has long been implicated in the development of depression.

It's one of the basic building blocks of life. And it's one of the all-star antidepressants. We all need vitamin B12 to make red blood cells and nerve cell membranes and to regulate the expression of our DNA and multiple other brain and body-based functions. It protects the brain and nervous system, regulates rest and mood cycles, and keeps the immune system functioning properly. A severe deficiency can lead not only to deep depression, paranoia and delusions, and memory loss, but also incontinence, the loss of taste and smell, and, eventually, physical brain shrinkage and dementia. The medical literature is filled with case reports of people with these conditions that a single shot of vitamin B12 cured. In fact, one of my favorite game-changing papers was a 2003 case report of a lifelong vegetarian who experienced a month and half of progressively worsening depression. Eventually she began to hear voices and feel paranoid. The fifty-two-year-old postmenopausal woman ultimately became what's called catatonic, which meant she was awake and alive but nonresponsive, and largely in an otherwise vegetative state. You would automatically assume this was a serious case of severe pathology, right? She was treated with electroconvulsive therapy and antipsychotics to no avail. And then she was transferred to another hospital, where they happened to test her levels of vitamin B12. Guess what: That's when they discovered she was a tad on the low side, and after receiving a vitamin B12 injection, she fully recovered. She was back to her old self quickly—her healthy self from 14 years previously—and needed no more treatment. While it may be one of the more extreme cases, it's emblematic of how a simple but critical deficiency can be at the casual root of psychiatric manifestations and subsequent high-risk interventions.

Some two-fifths of the population is severely deficient in B12 for a variety of reasons, from poor diet and dysbiosis (a disrupted gut flora) to use of medications like acid-reflux (e.g., Prilosec and Nexium, what are referred to as "proton-pump inhibitors") and diabetes drugs. Vegans and vegetarians may have to extra cautious about becoming deficient because the richest source of vitamin B12 is found in animal products such as fish, poultry, meat, and eggs (hence the case of the lifelong vegetarian—it eventually caught up with her).

It's standard in my practice to order a simple blood test to determine B12 levels in patients. It's practically a no-brainer for me today, as I know I can meaningfully move the health needle for many patients with this simple intervention. (Deficiency is traditionally defined as being below 150 to 200 pg/mL (picogram/milliliter), but you want to be above 600 pg/mL for optimal health.) I am especially vigilant about pregnant women, for babies born to a mother deficient in B12 are at serious risk for neurological symptoms such as lethargy, developmental delays, and delayed cognitive and motor development.

So you must ask yourself: Is your depression being fueled by low B12? Could you cure your depression and get on with you life via a B12 supplement that costs as much as a ticket to a movie for a month supply?

Tip: Vitamin B12 comes in a few different forms, which vary in efficacy and safety. Cyanocobalamin is the most commonly used form of the nutrient. It's less expensive, but it is not found in nature, and its metabolism may release small amounts of cyanide into the system. That's right: cyanide. While this could never be enough to cause cyanide poisoning, it's a potential issue for people who have impaired detox as a result of genetic issues, nutrient deficiencies, or chronic illness. The most desirable form of B12 is methylcobalamin, which is the form found produced by our gut bacteria. So when you're looking for a B complex, make sure it contains B12 as methylcobalamin (or hydroxocobalamin or adenosylcobalamin) in addition to the other B vitamins.

Extra Tip: When you get your vitamin B12 levels checked, also have your homocysteine levels checked too. This is a more accurate and more sensitive method of screening for vitamin B12 deficiency. Homocysteine is a potentially inflammatory protein that must be metabolized by B12 and folate. Optimal levels of homocysteine are between 7 and 10 micromoles per liter of blood. Typically a homocysteine over 8 is a red flag for inflammation that may be responsive to B12 supplementation.

This is one of many ways in which depression (and fatigue, and brain fog, etc.) presents an invitation to recalibrate, rebalance, and reexamine ways in which to better support our bodily organism.