Plant Vitamins

While we certainly get the lion’s share of our vitamins from plants, how do those vitamins serve the plants that produce them? And do we need to add vitamins to our soil?
 
Let’s find out.

Green leaves with white capsules (pxhere)

First, the study of vitamins as they are used by plants is relatively new. The factual data is limited, while the assumptions and false claims are already running rampant. Before adding anything to your soil, conduct a lab-based soil test.
 
Next, let me tell you that the currently available research is some pretty thick reading. I’m not going to delve deeply because I want you to keep reading and I want what you read to be useful. If you want more in-depth information, check out  “Benefiting others and self: Production of vitamins in plants” by Yufei Li, et al, and “Vitamins and Their Effects on Plant” by Hayder Abid Alrazzaq, et al.
 
We will take a far more simplified view while retaining the facts.
 
What are vitamins?
 
There are four nutrient groups: amino acids, fatty acids, minerals, and vitamins. Vitamins are molecules, or groups of molecules, used in very small amounts by living things for proper metabolism. Very often, plants can make or synthesize their own vitamins, but rarely can they produce as much as they need. The rest must come from elsewhere.
 
How do plants use vitamins?
 
Plants use vitamins much the way we do. Vitamins are like puzzle pieces [coenzyme regulators] that bring together important physiological processes:

• Counteract environmental stress
• Fight disease
• Increase crop yields
• Maintain proper cell function
• Protect against rot
• Regulate growth and development
• Resist salinity stress
• Support photosynthesis

 
But too much of a good thing can be a bad thing. For example, too much vitamin B6 can make diseases worse for plants.
 
Which vitamins do plants use?
 
Plants use many of the same vitamins we do. I can tell you that reading the Latin names of some of these made it easy to see why we use abbreviated letters and numbers!
 
Here is a list of the vitamins used by plants and what we currently know about them:

• Ascorbic acid (C)—Promotes vegetative and reproductive growth, activates photosynthesis, enhances seedling growth but delays flowering
• Biotin (H)—Regulates construction and destruction within the plant, critical to the Krebs cycle
• Cobalamin (B12)—Acts as a cofactor for several enzyme functions
• Ergocalciferol (D2)/cholecalciferol (D3)
• Folates (B9)—Promotes vegetative and reproductive growth and cell division, supports photosynthesis, helps fight against Pseudomonas syringae, cucumber mosaic, and several Xanthomonas/leafspot diseases
• Niacin/nicotinamide adenine dinucleotide (B3; NAD)—Primary focus on root development, DNA repairs, metabolism, pollen fertility, silique growth, and stress responses
• Pantothenic acid (B5)—Promotes vegetative and reproductive growth, supports metabolism and photosynthesis
• Phylloquinone/menaquinones (K)
• Pyridoxine (B6)—Critical to early root development, an important part of most biochemical changes related to growth
• Retinol/β-carotene (A)—Growth regulator at the cellular and tissue level
• Riboflavin (B2)—Used in breaking down amino acids, photosynthesis, and other metabolic processes, helps combat bacterial speck in tomatoes, downy mildew, Alternaria leaf spot, and tobacco mosaic, helps produce growth hormones (auxins)
• Thiamine (B1)—Functions as a growth regulator and stimulator, reduces membrane permeability, improves photosynthesis, activates antioxidant enzymes, especially important when growing corn, helps fight leaf blight and sheath blight, and is a major player in the Krebs Cycle, nitrogen assimilation, and the Calvin cycle
• Tocopherol/tocotrienol varieties (E)—Maintains membrane stability, found throughout the plant in chloroplasts where it supports photosynthesis, regulates growth and development, and reduces the negative effects of physical stress

 
We also know embryonic and early seedling death can occur when the synthesis of vitamins B1, B2, B3, B5, B6, B7, B9, and E is disrupted. Note that I said disrupted and not absent from the soil. Plants manufacture many of these vitamins.
 
But how does all this help you be a better gardener?
 
Your soil test will not tell you which vitamins are present. Vitamin deficiencies and toxicities in plants is a relatively new science. There are no handy tips, tools, tests, or solutions. Not yet anyway.
 
As the nutritional values of many food crops continue to decline, research has focused on increasing vitamin levels in the plants we eat. This process is called biofortification. In many cases, these plants are genetically modified (GMOs). Other times, it is simply a matter of selective breeding. Unfortunately, I do not have access to a list of which is which at this time. The good news is that as more research is conducted, we are likely to have access to more useful information.
 
The best way to ensure your plants have everything they need to grow and thrive is to top dress your soil with alfalfa meal, blood meal, compost, and aged manure. And keep reading and learning about new discoveries related to plants, vitamins, and gardening!

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Did you know that the word vitamin started as “vital amines”? Vita is Italian for ‘life’ and amines are compounds that contain nitrogen. While not all vitamins contain nitrogen, the term is now so commonly used that we keep it. Now you know.