Understanding the Natural Sources of Pyridoxal 5 Phosphate (P5P)

December 14, 2025 •

4 min read

Over 140 different enzymatic reactions in the body rely on pyridoxal 5 phosphate (P5P) as a coenzyme. While P5P is the active form of vitamin B6, it is not found directly in food but is rather converted by the body from the B6 vitamers present in various natural sources.

Quick Summary

This article explains that pyridoxal 5 phosphate (P5P) is not found directly in food but is synthesized by the body from other forms of vitamin B6. It details the best dietary sources of vitamin B6 and how the body utilizes them.

Key Points

P5P is an active vitamin B6 coenzyme, not a food nutrient: Pyridoxal 5 phosphate (P5P) is the final, active form of vitamin B6, which is created inside the body from other B6 compounds consumed through food.
Rich food sources provide the precursors: Foods like salmon, chickpeas, beef liver, and potatoes contain other forms of vitamin B6 (pyridoxine, pyridoxal) that your body converts into P5P.
Bioavailability varies between sources: The bioavailability of vitamin B6 from food is generally high, but it can be affected by food processing methods. P5P supplements offer 100% bioavailability by bypassing the body's conversion process.
A balanced diet is key for natural P5P production: Consuming a variety of animal and plant-based foods ensures a steady supply of vitamin B6 for your body to convert into P5P.
Supplementation is an alternative for direct P5P: While food is the primary source of B6 precursors, P5P supplements are available for those who may have trouble converting the vitamin efficiently.

The Core Concept: From Vitamin B6 to P5P

To understand the natural sources of pyridoxal 5 phosphate, it is crucial to recognize that P5P itself is not typically consumed directly through food. P5P, or pyridoxal 5'-phosphate, is the metabolically active coenzyme form of vitamin B6. Vitamin B6 is actually a collection of six compounds, including pyridoxine, pyridoxal, and pyridoxamine, all of which the body can convert into P5P. When you eat foods containing these B6 compounds, your liver is responsible for their metabolism and conversion into the usable P5P form. This means a healthy and balanced diet, rich in a variety of B6-containing foods, is the true "natural source" for your body's P5P supply.

Best Dietary Sources of Vitamin B6

A wide range of foods, both animal and plant-based, are excellent sources of vitamin B6. Including a mix of these in your diet ensures you provide your body with the building blocks it needs to produce P5P.

Animal-Based Sources

Fish: Fatty fish like salmon and tuna are some of the richest sources of vitamin B6. Just a three-ounce serving of cooked yellowfin tuna can provide over half of the daily value.
Beef and Poultry: Meats such as beef (especially beef liver), chicken breast, and turkey are significant contributors of B6. Leaner cuts are often recommended to limit saturated fat intake while still benefiting from the vitamin content.
Organ Meats: Offal, particularly beef and chicken liver, is packed with vitamin B6 and other essential nutrients, though its popularity has waned.
Eggs and Dairy: Eggs provide a respectable amount of vitamin B6. Dairy products, especially those high in whey protein like ricotta and cottage cheese, also contain the vitamin.

Plant-Based Sources

Legumes: Chickpeas, in particular, are a standout source. One cup can supply a large portion of your daily recommended intake. Other legumes like lentils are also beneficial.
Starchy Vegetables: Potatoes and sweet potatoes are excellent sources of vitamin B6, providing a solid amount per serving.
Fruits: Non-citrus fruits like bananas, avocados, and watermelon are good fruit-based sources of vitamin B6.
Nuts and Seeds: Nuts, especially pistachios and sunflower seeds, are another great plant-based option.
Leafy Greens: Vegetables such as spinach contain vitamin B6 along with other vitamins and minerals.

Fortified Foods

Breakfast Cereals: Many breakfast cereals are fortified with a wide range of vitamins and minerals, including B6, to help fill common dietary gaps.
Enriched Grains: Enriched rice and other enriched grain products often have B6 added back after processing. It is worth noting that while whole grains are naturally high in B6, the refining process can strip away these nutrients, making fortification a common practice.

Bioavailability: Food vs. Supplements

While food sources are the most common way to get vitamin B6, dietary supplements are also available and provide P5P directly. This offers a bypass around the metabolic conversion process in the liver, making the P5P immediately bioavailable. For most people with a healthy diet and no underlying conditions, food sources provide ample vitamin B6, with bioavailability estimated at around 75%. However, those with impaired liver function or certain genetic mutations may have difficulty converting B6 effectively and could benefit from direct P5P supplementation, under the guidance of a healthcare professional.

Comparison of Vitamin B6 Sources


Food Source	Type	Vitamin B6 Content (Relative)	Notes	Bioavailability (Relative)	Ease of Preparation	Impact of Cooking	Cost	Availability
Salmon/Tuna	Animal	Very High	Excellent source of protein and Omega-3s.	High	Moderate	Cooking can slightly reduce content.	Moderate to High	High
Beef Liver	Animal	Extremely High	Nutrient-dense, but less common in modern diets.	High	Moderate	Needs careful preparation to retain texture.	Low to Moderate	Moderate
Chickpeas	Plant	High	Versatile legume, great for vegetarian diets.	Moderate	Low	Canned and cooked options readily available.	Low	High
Potatoes	Plant	Moderate	Staple crop, easy to prepare.	Moderate	Low	Cooking methods (boiling, baking) vary impact.	Low	High
Banana	Plant	Moderate	Portable and convenient snack.	Moderate	Very Low	Minimal preparation.	Low	High
Fortified Cereals	Processed	Variable	Can provide a boost, but content varies widely.	Moderate	Very Low	Ready-to-eat.	Low	High
P5P Supplements	Non-Food	Direct	Bypasses the need for metabolic conversion.	Highest	Very Low	Taken as a capsule or tablet.	Variable	High

Conclusion

The notion of seeking "natural sources" of pyridoxal 5 phosphate leads us to the wide array of foods containing its precursor, vitamin B6. From the high concentrations found in animal proteins like fish and beef liver to the reliable plant-based options such as chickpeas and potatoes, maintaining adequate B6 intake is achievable through a diverse diet. While supplementation with P5P is an option for certain individuals, it is the consistent consumption of these vitamin B6-rich foods that naturally supports your body's vital metabolic processes.

Authoritative Link: National Institutes of Health - Vitamin B6 Fact Sheet

Frequently Asked Questions

No, pyridoxal 5 phosphate (P5P) is not typically found directly in foods. Instead, foods contain other forms of vitamin B6 that the body converts into the active P5P form, mainly in the liver.

Excellent sources of vitamin B6 include animal proteins like salmon, tuna, beef liver, chicken breast, and pork, as well as plant-based options such as chickpeas, potatoes, bananas, and fortified cereals.

The body, primarily through the liver, converts the various forms of vitamin B6 (pyridoxine, pyridoxal, and pyridoxamine) found in food into the active coenzyme pyridoxal 5 phosphate (P5P).

Yes, many fortified foods, including breakfast cereals and enriched grains, have vitamin B6 added during processing and can be a good source of the vitamin.

Like many water-soluble vitamins, some vitamin B6 can be lost during food preparation and cooking, particularly with high heat or prolonged cooking in water.

P5P supplements bypass the body's need to convert vitamin B6 into its active form, which can be beneficial for individuals with impaired liver function or certain genetic conditions that affect this conversion process.

Yes, a well-balanced vegetarian or vegan diet can provide sufficient vitamin B6 through sources such as chickpeas, nuts, potatoes, bananas, and fortified grains.