A review of the medical research on zinc shows that when it is taken within one day of the first symptoms, it can cut down the time you have a cold by about 24 hours. It also greatly reduces the severity of symptoms. The authors of the review did not make any suggestions as to what type of zinc product to buy. They also did not suggest an optimal dose or formulation, stating that more research was needed before such a recommendation could be made. Zinc supplements also have downsides -- they can cause nausea and a bad taste in the mouth, and they may interfere with your body's uptake of other key minerals. According to the New York Times: "Zinc experts say that many over-the-counter zinc products may not be as effective as those studied by researchers because commercial lozenges and syrups often are made with different formulations of zinc and various flavors and binders that can alter the effectiveness of the treatment." Colds are transmitted only by droplets, such as from sneezing, that come from a person who's infected.
These droplets can, however, remain on surfaces for some time. Colds normally last about seven days. Cold medicines are not recommended for children under 4, and no cold medicines are cures -- they only relieve symptoms. Washing your hands is still the number one recommended way to keep yourself free of colds.The most common medication used in women with PCOS is the insulin-sensitizer metformin. Research is strongly showing that long-term use of metformin and at high doses (1.5mg or higher daily) can deplete levels of vitamin B12. A deficiency of vitamin B12 can cause permanent neurological and nerve damage as well as mood changes and decreased energy. Here’s what you need to know to avoid a vitamin B12 deficiency if you take metformin. Metformin is a medication that became available in the U.S. in 1995 for the treatment of type 2 diabetes. Metformin is the most widely used medication used to lower insulin levels in those with polycystic ovary syndrome. Other names for metformin include glucophage, glucophage XR, glumetza, and fortamet.
Metformin lowers blood glucose levels in three ways: Metformin use may affect the absorption of vitamin B12 possibly through alterations in intestinal mobility, increased bacterial overgrowth, or alterations of the vitamin B12-intrinsic factor complex. Metformin can cause a malabsorption in B12 due to digestive changes, which leads to the binding of B12-intrinsic factor complex (intrinsic factor is needed to absorb B12 in the gut) and a reduction of B12 absorption. The largest study thus far to examine the link between metformin and vitamin B12 is the Diabetes Prevention Program Outcomes Study (DDPOS). This study looked at B12 levels of individuals with prediabetes who took 850 mg Metformin 2x/day and compared them to those taking a placebo. At 5 years, 4.3% of the metformin users had low levels of B12 (<203 pg/ml) vs 2.3% of placebo takers and 19% of metformin users had borderline low B12 levels (204 –298 pg/ml) compared with 9.5% of placebo. Vitamin B12 levels decreased over the years among individuals who took metformin.
At 13 years, 7.4% of metformin users had low B12 levels and 20.3% had borderline low levels. One study published in the Journal of Clinical and Diagnostic Research found that 33% of individuals who took metformin were deficient in Vitamin B12 A 2015 systematic review and meta analysis which looked at a large number of studies, concluded that metformin treatment is significantly associated with an increase in incidence of B12 deficiency and reduced serum VB12 levels. Nearly a third of obese adolescents with clinical insulin resistance had a low or borderline serum B12 status in a study published in Nutrients. The prevalence of vitamin B12 deficiency in metformin-treated type 2 diabetes patients in Korea was 9.5%. Vitamin B12 deficient patients had longer duration of metformin use and higher daily metformin dose.Vitamin B12 deficiency was defined as vitamin B12 ≤ 300 pg/mL without folate deficiency (folate > 4 ng/mL). Studies done investigating metformin use in women with PCOS are severely lacking.
There is much more data on people with diabetes who take metformin with the majority of the evidence showing metformin decreases B12 levels. As for studies done in women with PCOS, here is what the evidence shows: One study in Nutrients found serum B12 levels declined and reached significant lower levels after just six months of treatment in women with PCOS taking 1.5-2.5 grams of metformin daily. In 2009, Kaya et al. found that vitamin B12 concentrations were significantly lower in obese PCOS women in comparison with obese control women. Women with PCOS tend to take higher amounts of metformin (average dose is 1,500-2,000 mg daily) than those with diabetes to help manage insulin resistance. Both long-term use and high dosage intake as seen in the PCOS population, are risk factors for vitamin B12 deficiency. Vitamin B12 is a water-soluble vitamin that is required for proper red blood cell formation, neurological function, and DNA synthesis. There’s some evidence that vitamin B12 may help prevent heart disease and possibly even Alzheimer disease.
This vitamin is found primarily in animal foods, such as beef, seafood, eggs, and dairy products, which is why some vegans are at risk for a B12 deficiency (click here for a list of food sources of B12). Elderly people are often at risk for deficiency as well, due to problems with absorption from the gastrointestinal tract. Symptoms of B12 deficiency include certain types of anemia, neuropathy (nerve damage), chronic fatigue, memory loss, confusion, mood changes and even dementia. Pernicious anemia, a severe form of long-term vitamin B12 deficiency is an autoimmune disease that affects the stomach. If you experience any of these symptoms, see your doctor immediately. Individuals who take metformin get B12 levels checked annually. A simple blood test can assess vitamin B12 status. Normal lab reference ranges may vary by lab. Values below approximately 170–250 pg/mL (120–180 picomol/L) for adults indicate a vitamin B12 deficiency. Elevated serum homocysteine and methylmalonic acid levels may also indicate a B12 deficiency.
Authors of the book, Could It Be B12, say levels to indicate a vitamin 12 deficiency are too low and that people with levels under 400 pg/mL could very well be deficient with B12 and have effects. All individuals age 14 or higher need 2.4 mcg B12 daily whether they take metformin or not. Women who are pregnant or nursing will need slightly more. Mandatory supplementation with B12 has now been proposed for those taking metformin. Taking a daily multivitamin containing 100% of the daily value (DV) for vitamin B12 may do the trick although many of our patients who take a mulitivitamin with B12 and are on high doses of metformin are still deficient in vitamin B12, requiring extra supplementation. The best absorbable form of Vitamin B12 is methlycobalimum. Taking vitamin B12 sublingual (under the tongue) is recommended for over the counter B12 supplements. Have you had your levels of Vitamin B12 checked? Share with us by leaving a comment below. Aroda VR, et al. Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study.
J Clin Endocrinol Metab. Ingole JR, Patel RD, Ingole SJ, Pandave HT. Opportunistic Screening of Vitamin B12 Deficiency in IT Professionals Presenting for Routine Health Check-up. J Clin Diagn Res. 2015 Dec;9(12):OC01-OC02. Niafar M, Hai F, Porhomayon J, Nader ND. The role of metformin on vitamin B12 deficiency: a meta-analysis review. Intern Emerg Med. 2015 Feb;10(1):93-102. Ho M, Halim JH, Gow ML, El-Haddad N, Marzulli T, Baur LA, Cowell CT, Garnett SP. Vitamin B12 in obese adolescents with clinical features of insulin resistance. Ko SH1, Ko SH1, Ahn YB1, Song KH1, Han KD2, Park YM3, Ko SH1, Kim HS1. Association of vitamin B12 deficiency and metformin use in patients with type 2 diabetes. J Korean Med Sci. 2014 Jul;29(7):965-72. Liu Q1, Li S1, Quan H1, Li J1. Vitamin B12 status in metformin treated patients: systematic review. Greibe E, Trolle B, Bor MV, Lauszus FF, Nexo E. Metformin lowers serum cobalamin without changing other markers of cobalamin status: a study on women with polycystic ovary syndrome.