What’s the best B12 injection dosage for weight loss?
Where’s the best place to inject B12 for weight loss?
What are the benefits of B12 shots for weight loss?
We get these kinds of questions relating B12 shots to weight loss quite often. We’d like to shed some light on the subject, because this idea of B12 magically obliterating fat and making you slim seems to be circulating a lot around the internet.
We understand – it’s a sexy idea. Why invest hours at the gym and conquer the discipline to follow a clean diet, when you can just inject yourself with B12 and be done? If history has taught us anything, it’s that people will always look for path of least resistance.
This idea is far from accurate, yet many companies embraced it so that they could sell more B12. However, buying B12 shots for weight loss purposes is a waste of money.
Let’s see why.
B12 Injections and Weight Loss
The idea of B12 shots leading to weight loss probably came from the observational studies that linked low vitamin B12 to a higher body-weight:
Low vitamin B12 level was associated with obesity and overweight, but not with insulin resistance, metabolic syndrome and gender. Vitamin B12 was negatively correlated only with body mass index.Association of vitamin B12 with obesity, overweight, insulin resistance and metabolic syndrome, and body fat composition; primary care-based study
In a large nationally representative sample of U.S. adults, higher serum vitamin B12 levels were inversely associated with obesity. Further investigation is needed to understand the underlying mechanisms.Inverse Association Between Serum Vitamin B12 Concentration and Obesity Among Adults in the United States
Obesity in children and adolescents was associated with an increased risk of low vitamin B(12) concentration. We recommend that dietary assessment of obese children should include an estimation of vitamin B(12) intake. The possibility of vitamin B(12) deficiency in addition to other micronutrient deficiencies should be considered in obese children.Obese children and adolescents: a risk group for low vitamin B12 concentration
In conclusion, our study has replicated the previous Indian findings of associations between lower serum B12 and higher obesity and insulin resistance during pregnancy in a non-diabetic White British population. These findings may have important implications for fetal and maternal health in obese pregnancies.Lower Circulating B12 Is Associated with Higher Obesity and Insulin Resistance during Pregnancy in a Non-Diabetic White British Population
Serum concentrations of vitamin B-12 and folate were inversely associated with BMI.Low serum vitamin B-12 and folate concentrations and low thiamin and riboflavin intakes are inversely associated with greater adiposity in Mexican American children
Children born to mothers with low B12 levels may have excess fat accumulation which in turn can result in higher insulin resistance and risk of T2D and/or CVD in adulthood.LOW VITAMIN B12 AND LIPID METABOLISM: EVIDENCE FROM PRE-CLINICAL AND CLINICAL STUDIES
Increase in body mass index-standard deviation score was associated with a decrease in vitamin B12 levels.Negative correlation among vitamin B12 levels, obesity severity and metabolic syndrome in obese children: A case control study
The Correct Way to See It
On average, people with low B12 are less healthy than people with normal B12 levels. Also on average, overweight people are less healthy than people of a healthy weight. So, why then would it be surprising that people with low B12 tend to be more overweight? This, of course, doesn’t necessarily mean that the low B12 is what’s causing the weight gain. It could be anything, from bad nutrition habits to co-morbidities:
Lower serum vitamin B12 levels have been related to adverse metabolic health profiles, including adiposity. We used a Mendelian randomization design to test whether this relation might be causal.Genetic determinants of serum vitamin B12 and their relation to body mass index
We found no support for a causal role of decreased serum vitamin B12 levels in obesity. However, our study suggests that FUT2, through its regulation of the cross-talk between gut microbes and the human host, might explain a part of the observational association between serum vitamin B12 and BMI.
Although, B12 could be part of it. We honestly don’t know to what extent B12 affects weight-change. But due to it’s role in the metabolism, it’s a possibility:
Based on nationally representative data, we found an inverse and significant association between serum vitamin B12 levels and obesity in a dose-response manner. Compared with individuals with higher vitamin B12 concentrations, those with lower vitamin B12 concentrations were more likely to be obese. These associations were independent of demographic, socioeconomic, lifestyle factors, use of medications that could have an effect on serum vitamin B12 levels, dietary supplement use and fasting time. To our knowledge, this is the largest study to date regarding the association of serum vitamin B12 levels with obesity in the general population. Previous studies on the association of serum vitamin B12 levels with obesity in adults have yielded inconsistent findings. Our results are consistent with some previous studies where serum vitamin B12 levels were inversely associated with obesity.Inverse Association Between Serum Vitamin B12 Concentration and Obesity Among Adults in the United States
There are several possible explanations for these associations. One possible explanation is that low serum vitamin B12 levels would trap folate as 5-methyltetrahydrofolate, prevent the generation of methionine from homocysteine, and therefore reduce protein synthesis and lean tissue deposition. It could also be due to the adipocyte dysfunction linked to low vitamin B12 levels through cellular inflammation. Another possibility is that obesity could lower serum vitamin B12 levels through decreased dietary intake or absorption, increased catabolism, and sequestration in adipose tissue, or changes in the gut microbiota profiles which could affect the metabolism of vitamin B12. Interestingly, a recent study in Danish population showed that lower serum vitamin B12 concentrations were significantly associated higher BMI, but a genetic risk score related to vitamin B12 concentrations associated variants was not associated with BMI. The causal relation between vitamin B12 status and obesity warrants further investigation.
B vitamins are enzyme cofactors that play an important role in energy metabolism. The aim of this study was to elucidate whether B vitamin administration can reduce body weight (BW) gain by improving energy metabolism-related enzyme activities in rats fed on a highfat diet.B Vitamins Can Reduce Body Weight Gain by Increasing Metabolism-related Enzyme Activities in Rats Fed on a High-Fat Diet
Supplementation with B vitamins could effectively reduce BW gain and plasma levels of lipids by improving energy metabolism-related enzyme activities in rats, thus possibly providing potential benefits to humans.
The Bottom Line
There’s a clear association between lower B12 levels and a higher body-weight.
But, it doesn’t necessarily mean that increased B12 levels cause weight loss. It could very well be co-existing conditions or habits in B12-deficient folks, which are causing the weight gain. However, due to B12’s effect on the metabolism, it is possible that B12 deficiency could play some part in weight gain, to whatever degree.
So, should you take B12 shots for weight loss?
You should take B12 shots if you suffer from B12 deficiency, especially if you are not able to absorb B12 through the stomach (pernicious anemia). In that case, B12 injections will fix your anemia, stabilize your metabolism, and likely help manage body-weight.
But, if you are not deficient at all (check out our symptoms list), then the B12 likely won’t do much. Once you have healthy stores of B12, there’s no functional day-to-day benefit to having more of it. Plus, the body very quickly urinates any excess of B12.
In summary, there’s no shortcut. There are many applications to B12 shots, but weight loss isn’t one of them. We highly suggest B12 injections for fixing a deficiency or treating pernicious anemia, but for pure weight loss purposes – there’s no point.
Eat clean. Cut out the junk. Start moving.
There’s no such thing as magic.