How much vitamin B3 is in rice?

January 4, 2026 •

4 min read

According to the National Institutes of Health, one cup of cooked brown rice contains roughly 5.2 mg of niacin (vitamin B3), making it a much more significant source than its processed counterpart. Therefore, how much vitamin B3 is in rice depends heavily on whether it is a whole grain or has been enriched through processing.

Quick Summary

The niacin (vitamin B3) content of rice varies significantly by type, with brown rice offering substantially more natural niacin than unenriched white rice. Enriched white rice has some vitamins added back, but brown rice remains the superior whole-grain source of this essential nutrient.

Key Points

Processing Matters: Brown rice contains substantially more naturally occurring vitamin B3 than white rice because it retains the nutrient-rich bran and germ.
Enrichment Helps: Most white rice in the U.S. is enriched, meaning niacin and other nutrients are added back after processing, though typically at lower levels than in brown rice.
Cooking Method Impact: Water-soluble niacin can be lost when rice is cooked in excess water and then drained; using the absorption method retains more vitamins.
Brown Rice is a Superior Source: A single cup of cooked brown rice provides approximately one-third of the recommended daily value of niacin.
Bioavailability Consideration: Some niacin in brown rice is bound to other compounds, which can affect its absorption, but the overall higher quantity still makes it a better natural source.
Overall Diet is Key: The body can also produce niacin from the amino acid tryptophan, emphasizing that overall diet is more important than focusing on a single food item.

A Tale of Two Grains: Understanding the Niacin Difference

Understanding how much vitamin B3 is in rice starts with understanding the rice grain itself. A rice grain is composed of several parts: the bran, the germ, and the endosperm. Brown rice is a whole grain, meaning only the inedible outer husk is removed. It retains the nutrient-rich bran and germ, which contain the majority of the grain's vitamins and minerals, including niacin. White rice, on the other hand, is polished, a process that removes the bran and germ, along with most of the natural niacin, fiber, and other vitamins.

The Role of Enrichment

To combat nutritional deficiencies caused by the processing of white rice, many manufacturers enrich the grain. This process adds back certain nutrients that were lost during milling, including niacin, thiamin, and iron. This makes enriched white rice a much better source of vitamin B3 than its unenriched counterpart, although it still doesn't match the naturally high levels found in brown rice. For example, one study notes that the milling process can destroy up to 67% of vitamin B3 in rice.

Niacin Content Comparison: Brown vs. White Rice

The following table illustrates the significant difference in niacin content between different types of rice. It highlights why choosing a less-processed grain can have a major impact on your nutrient intake.


Rice Type	Niacin (Vitamin B3) per 1 cup, cooked	% of Daily Value (approx.)
Brown Rice (cooked)	5.2 mg	33%
White Rice, Enriched (cooked)	2.3 mg	14%
White Rice, Unenriched (cooked)	0.7 mg	4-5% (based on standard 16mg DV)

The Effect of Cooking on Vitamin B3

When considering how much vitamin B3 is in rice, it's also important to factor in the cooking process. Niacin is a water-soluble vitamin, meaning it can leach into the cooking water. However, niacin is also relatively stable when exposed to heat compared to other B vitamins. The method of cooking plays a crucial role in nutrient retention:

Conventional Boiling: This method, which involves cooking rice in a large pot of water and then draining the excess, can result in a higher loss of water-soluble vitamins like niacin. The more water you use and the more you drain, the greater the potential vitamin loss.
Absorption Method (e.g., Rice Cooker): Cooking rice using the absorption method, where all the water is absorbed by the grain, helps to retain more of the water-soluble vitamins. This is because the nutrients are not poured out with the excess water.

Maximizing Niacin Retention

To get the most vitamin B3 from your rice, follow these simple tips:

Choose Brown Rice: As the natural source of higher niacin, brown rice is the best starting point for a B3-rich meal.
Use the Right Cooking Method: Whenever possible, use an absorption method for cooking, such as a rice cooker or measuring the water precisely for stovetop cooking.
Avoid Excessive Rinsing: Rinsing rice can also wash away some of the water-soluble vitamins, especially in enriched varieties where the coating can be affected. Wash only when necessary and don't overdo it.

Niacin Bioavailability and Tryptophan

While brown rice contains more total niacin, some of its niacin is bound to compounds like polysaccharides and glycopeptides, which can limit its absorption in the body. The body can, however, also synthesize niacin from the amino acid tryptophan, which is found in a variety of other foods. This means a person's total niacin status depends on their overall diet, not just their rice consumption.

A Broader Nutritional Perspective

While the focus here is on how much vitamin B3 is in rice, it's worth noting the broader nutritional context. The choice between brown and white rice impacts the intake of many other nutrients as well. Brown rice is also a good source of fiber, manganese, selenium, and copper, all of which are significantly reduced or completely removed during the milling process for white rice. While enriched white rice adds back key nutrients, it does not replace the fiber and many other beneficial compounds found in the whole grain. For optimal nutrient intake, dietitians generally recommend prioritizing whole grains like brown rice. Further information on niacin can be found on the NIH Office of Dietary Supplements fact sheet.

Conclusion: Making an Informed Choice

Ultimately, the question of how much vitamin B3 is in rice has a clear answer: brown rice contains significantly more naturally occurring niacin than unenriched white rice, while enriched white rice has some added back. For those seeking to maximize their intake of natural B vitamins and other nutrients, brown rice and other whole grains are the superior choice. However, enriched white rice still provides a valuable amount of niacin and is a far better option than non-enriched white rice, particularly in diets where a variety of other niacin-rich foods are not regularly consumed. By understanding the nutritional differences and the effects of preparation, you can make informed choices to optimize your dietary health.

Frequently Asked Questions

Yes, brown rice has significantly more naturally occurring vitamin B3 (niacin) than unenriched white rice because the milling process that creates white rice removes the bran and germ, where most of the niacin is stored.

Enriched white rice has niacin and other B vitamins added back to it after processing to replace what was lost during milling. Unenriched white rice contains very little niacin naturally. Therefore, enriched white rice has much more vitamin B3 than unenriched white rice.

Cooking can reduce the vitamin B3 content of rice, especially if it is cooked in a large amount of water that is then drained. This is because niacin is water-soluble. To minimize loss, use a cooking method where the rice absorbs all the water.

To maximize your niacin intake, choose brown rice over white rice. When cooking, use the absorption method (like with a rice cooker) to prevent water-soluble vitamins from being poured out with excess water.

Yes, some of the niacin in brown rice is bound to certain compounds, which can limit its absorption. However, the total amount of niacin in brown rice is still higher than what is found naturally in unenriched white rice, even with absorption limitations.

For enriched white rice, excessive rinsing can wash away the added vitamin coating and reduce the vitamin B3 content. For brown rice, which contains natural niacin within the grain, the impact of rinsing is less significant.

Excellent sources of niacin include animal products like beef liver, chicken breast, and tuna. Plant-based sources include peanuts, sunflower seeds, and nutritional yeast, which is fortified and extremely high in niacin.