The B vitamins are important in diabetes management for two reasons. First, all of the B vitamins participate in chemical reactions taking place in your cells to harvest the energy from fats, protein, and carbohydrates, the energy that fuels everything from muscle movement to body heat to transporting glucose from your small intestine into your bloodstream during digestion.
The second reason B vitamins are important to diabetes management relates to where you find them and how to make the healthiest choices. Most likely you recognize thiamine, riboflavin, and niacin because a long-standing Food and Drug Administration bread enrichment program requires the addition of these B vitamins to refined (white) flours and bread products.
Why? Because refining whole grains by removing the bran and germ also removes the natural B vitamins you could have gotten by choosing whole grains in the first place. Choosing carbohydrate foods like grains is an important part of managing diabetes in your daily eating, and getting naturally occurring B vitamins along with your carbohydrate choices is one reason choosing whole grains is so important.
There are eight different vitamins grouped into what’s called the vitamin B complex — B1, B2, B3, B5, B6, B7, B9, and B12. Some you will know better by their actual names — thiamine (B1), riboflavin (B2), and niacin (B3). Others, like pyridoxine (B6) and cobalamin (B12) you’re more likely to know by the number.
Beriberi, a sometimes deadly condition that damages the nervous and cardiovascular systems, is caused by a deficiency in thiamine, vitamin B1. This condition was commonly observed among poorer Asians who lived on a diet of virtually nothing except polished rice. Experimenters eventually discovered that adding back the bran and germ, which contain the thiamine, could prevent beriberi.
Pellagra, caused by a deficiency of niacin, vitamin B3, spread across Europe after the introduction of corn from the Americas as a staple food. Researchers eventually learned that the native Americans and Mesoamericans treated their corn (maize) with alkali, like wood ashes or lime, making the niacin in corn available for digestive absorption, and explaining why pellagra was unknown among the native cultures.
The table lists the eight B vitamins, their function, and the best dietary sources for getting these essential nutrients.
| Vitamin and Daily Amount | Compound | Function | Source |
|---|---|---|---|
| B1 (1–1.5 mg/day) | Thiamine | Central role in extracting energy from carbohydrates, production, and cell metabolism DNA | Whole grain and enriched grain products, pork, liver |
| B2 (1.1–1.3 mg/day) | Riboflavin | Helps produce energy in cells, supports cell growth, helps regulate metabolism | Beef liver, milk and yogurt, spinach |
| B3 (14–16 mg/day) | Niacin | Energy production and cell growth, facilitates glucose and fat metabolism, helps enzyme function | Turkey breast, peanut butter, beans, and yogurt |
| B5 (5 mg/day) | Pantothenic | Helps produce energy in cells, involved in synthesizing amino acids, fatty acids, neurotransmitters, and antibodies | Yogurt, salmon, sweet potato, corn, egg, whole grains |
| B6 (1.3–1.7 mg/day) | Pyridoxine | Helps synthesize amino acids, helps immune system, helps produce hemoglobin, antibodies and insulin | Potato, banana, garbanzo beans, fish |
| B7 (30 mg/day) | Biotin | Helps produce energy in cells, regulates hormone synthesis, key role in metabolizing fats, protein, and carbohydrate | Egg, cottage cheese, peanuts, whole grain |
| B9 (400 mg/day) | Folate | Makes new cells, helps form hemoglobin, reduces risk for heart disease, crucial to fetal development | Spinach, beans, whole grains, avocado |
| B12 (2.4 mg/day) | Cobalamin | Makes red blood cells, helps form protective sheath for nerves, crucial role in cell division | Salmon, beef, yogurt, shrimp, no plant sources |
It should be noted that the daily recommendations for these vitamins vary between men and women, and generally are significantly greater during pregnancy. Folate is especially important during pregnancy for preventing neurological birth defects.
It’s also important to point out that vitamin B12 is not provided by any plant sources of food. That makes this crucial compound a challenge for vegans to acquire, even in the tiny amount necessary. Strict vegetarians have to consume foods fortified with vitamin B12.
The consistent role of B vitamins in cell metabolism and energy production is related to their involvement with the biochemical cycle that produces the energy molecule adenosine triphosphate (ATP) from carbohydrates, fats, and protein. The members of this group of vitamins are participants in the formation of co-enzyme A, NAD, NADP, and other participants in this energy cycle, which is unnecessary to explain in detail, but absolutely essential for life.
Recent research has focused on thiamine, vitamin B1, as being especially important to diabetes health — thiamine is a key component of normal carbohydrate metabolism.
A 2007 study (Thiamine deficiency in diabetes mellitus and the impact of thiamine replacement on glucose metabolism and vascular disease) found that a sample of people with both type 1 and type 2 diabetes showed blood levels of thiamine 75 percent lower than normal because they were excreting thiamine in urine at a higher than normal rate.
A 2011 study (High prevalence of low plasma thiamine in diabetes linked to a marker of vascular disease) suggested that the metabolism of carbohydrates when thiamine levels are low produces by-products that may contribute to serious complications of diabetes, including arterial plaque buildup and neuropathy.
A small Pakistani study published in 2009 (High-dose thiamine therapy for patients with diabetes and microalbuminuria) improved kidney function among a group with type 2 diabetes by adding thiamine supplements to their diet.
The jury is still out as to whether thiamine supplementation is directly beneficial to diabetes health, and, if so, at what level. However, it seems clear that working plenty of thiamine-rich foods into your diet is a wise strategy. Whole or enriched grain products, lean meats (especially pork), fish, nuts, seeds, and beans are great dietary sources of thiamine.