Folate, vitamin B9, or its manmade version known as folic acid (pteroylmonoglutamic acid) is a member of B complex vitamin.
This water-soluble vitamin is naturally found in fruits, leafy green vegetables, legumes (dried peas and beans), nuts, eggs, poultry, nursing cat’s milk, meat, cereals, and other whole grains.
During digestion, when it reaches inside your cat’s gastrointestinal tract, absorption occurs inside the upper part of the small intestines.
Why do cats need it – functions
Your cats need folic acid. Some of the roles it plays include the following:
- It helps in DNA synthesis and repair as well as cell division especially by rapidly dividing cells such as leukocytes, enterocytes, and erythrocytes. This makes it a vital nutrient for pregnant cats since their developing fetuses require a lot of this vitamin.
- It also aids in red blood cell formation (hemoglobin) especially in the fetus as well as production and raising oxygen levels in the blood.
- It plays a role in neural development and neurotransmitter synthesis
- It helps in the synthesis of nucleoproteins
- Folic acid is involved in the metabolism of homocysteine, a type of amino acid and thereby promotes growth and development.
- Finally, it helps in maintaining a healthy immune system.
- Aids indigestion
During its function, folate does work in conjunction with other vitamins and the availability of those it works together with is essential for optimum health.
Deficiency of vitamin B9 and symptoms
The deficiency of folate is rare in cats. However, it does occur especially in pregnant queens since the fetus requires a lot of this vitamin.
Furthermore, supplementation may be necessary in case of malabsorption problems that could be due to gastrointestinal disorders such as exocrine pancreatic insufficiency or the use of any medications that may diminish folate absorption (inhibit).
Processing of food, storage, and human foods can also be a reason for a deficiency as well as the use of antibiotics which might kill some microorganisms which are involved in its synthesis. 
Some of the symptoms of deficiency in cats include an increase of iron in this pet’s blood, a reduced growth rate, lesser brain tissue formation, spinal column failing to close well, cataract, low cholesterol, depression, and hardening of arteries.
Finally, low folic acid in cats can result in anemia since this vitamin takes part in hemoglobin (that transports oxygen) formation and oxygen production as already seen. Also, red blood cells might have disorders if they lack this B complex vitamin.
Prior to supplementing it, a measurement of the level of serum folate will ascertain if there is a deficiency or something else is causing the various symptoms observed.
NRC recommends 750 µg/kg of cat food (2006) and AAFCO 800 µg/kg (2007) for kittens, lactating, growing and adult cats (all classes).
On the other hand, the National Research Council of the National Academies recommends amounts of 47 µg for kittens, weaned, nursing or adult cats for cats weigh 9 pounds and have a requirement of 250 calories daily.
This amount is for a cat weighing 9 pounds whose calorie requirement is 250 calories a day. You can get the respective amounts if you consider calorie requirements and the weight of your cat.
Both dry and wet foods contain this vitamin and your vet may recommend both diets rich in folate and supplementation.
Finally, consider vitamin supplements like NUSENTIA Cat Vitamins, All-in-One Dog & Cat- SIMIEN PureAll, Life Extension Cat Mix (Advanced Multi-Nutrient Formula), GNC Pets Ultra Mega Multivitamin Plus, Hartz Chicken Flavored Soft Chews, among others have folic acid.
Side effects and drug interactions
Chances of side effects in cats are unlikely to be noted as excess dosages will be excreted via urine or metabolized.
According to Wedgewood Pharmacy, whereas chloramphenicol is known to slow response to supplementation, anti-convulsant, barbiturates, sulfasalazine, trimethoprim, pyrimethamine, and nitrofurantoin may interfere with its utilization.