Vitamin K deficiency in Turtles and Tortoises
Though Vitamin K is slightly less talked about than Vitamins D, A and C – it is every bit as essential! For turtles, it is vital that they get a healthy amount in their diet, otherwise Vitamin K deficiency (also known as Avitaminosis K) may occur.
Vitamins play an essential role in turtle diets because they support a variety of biological functions and maintain tissues. Vitamin intake supports things like bone and shell strength, skin health and eyesight, for example.
For a long time, there was a misconception that Vitamin K deficiency was incredibly rare, or even impossible, because naturally occurring gut bacteria synthesise it. We thought, “how could turtles get a deficiency when they have a constant supply?”
More recently, however, scientists have begun to realise that regular, dietary Vitamin K intake is necessary, contributing to healthy growth, blood clotting and shell calcification.
In this article we’re going to look at what Vitamin K does, how to spot a deficiency, prevent it, and when to see a vet.
What is Vitamin K, and what does it do?
Just like Vitamin A, Vitamin K is fat soluble, meaning body tissues can store it for some time. This means it takes longer to develop a deficiency, but that overdose due to over supplementation is also more likely.
In nature, Vitamin K occurs as two main groups of molecules. These are phylloquinones, known as Vitamin K1, and menaquinones, known as Vitamin K2.
Vitamin K1 is found in plants where it plays a vital role in photosynthesis, as well as in certain bacteria and algae. Vitamin K2, on the other hand, is found in live prey or synthesised by bacteria in the gut.
Wild Chelonians (turtles and tortoises) use both vitamins K1 and K2, but obviously which type they need most of depends on their natural diet. In a nutshell, the more herbivorous a species is the more Vitamin K1 it needs, whereas carnivorous species will need more Vitamin K2.
Artificial Vitamin K is made from a chemical called menadione and is usually referred to as Vitamin K3. In captivity, Vitamin K3 has been proven adequate to supplement turtle diets, though many experienced keepers believe it’s better to go the all-natural route when possible.
In turtles and tortoises Vitamin K promotes healthy bone and shell calcification and a normal rate of growth in juveniles.
On top of this, it plays an essential role in blood clotting by helping animals to synthesise prothrombin. This is important because without it, minor injuries would bleed excessively and become major health issues.
How to spot Vitamin K Deficiency
Given that much of an animal’s Vitamin K intake may in fact be from its gut bacteria, its important to be extra vigilant following long-term treatment with antibiotics. In this exceptional case, it’s best to ask your vet’s advice at the time of treatment.
In adult animals, excessive bleeding from the gums/mouth or excessive bleeding from small wounds are the most common symptoms. Following this, the next major symptoms are a poor appetite and poorly calcified shell (feeling too flexible for its age). Notwithstanding, these are both also symptoms of Vitamin D deficiency – so try to rule this out first!
In juvenile animals there is a subtle, long-term symptom that indicates a deficiency before it gets serious: stunted growth.
In fact, in one study from 2019 found that weight gain in juvenile Chinese Soft-shelled turtles was lower in those fed less Vitamin K3.
So, your best bet for spotting a deficiency in young turtles is in fact to weigh them at regular intervals. I recommend weighing juveniles once a month in their first and second year, then once every 3 months in their third and fourth years.
Obviously, growth rates differ, but a good, steady rate of growth is a good sign.
Symptom summary:
- Poor appetite
- Poor growth in juveniles
- Bleeding gums/mouth
- Excessive bleeding from small injuries
- Poor shell calcification in adults/subadults
- (eventually) internal haemorrhage
How to prevent Vitamin K Deficiency
Given how subtle it can be, and its similarity to other deficiencies, prevention is your best bet for dealing with Vitamin K deficiency!
Obviously, the best way to prevent it is by providing a healthy, balanced diet for your pet. Always thoroughly research your turtle species’ diet and never rely on just one type of food, as this is certain to create problems.
It’s also worth recording what you feed them and when. Some keepers do this by simply keeping a little notebook next to the enclosure and writing an entry at each feeding. This allows you to monitor their diet over time and review it on occasion.
For aquatic turtles like Sliders, be sure to include high-quality turtle pellets in their diet. Good brands now have healthy amounts of Vitamin K and make supplementation unnecessary when part of a varied diet.
For carnivorous and omnivorous species like Box Turtles, supplements can be an effective way to make sure they have a steady Vitamin K intake – but don’t overdo it! Over supplementation can be just as harmful as a deficiency, so only supplement once or twice a month and never more than the manufacturer recommends.
For tortoises, read the next section.
When formulating a tortoise diet
When feeding tortoises, you obviously need to keep their Vitamin K requirements in mind. They need it on a regular basis, but not too much. This sounds easy, right? Just look up Vitamin K-rich veggies and there you go!
Unfortunately, it’s not that simple… In fact, you need to research several factors when deciding which vegetables to give your pet.
Certain plants do have healthy levels of Vitamin K1, but also contain phytotoxins, oxalates and goitrogens – all of which can do great harm if fed in excess. One example of this is Broccoli, which is high in both Vitamin K and goitrogens, which can cause poor thyroid function and kidneys stones.
The problem is that these same vegetables are great for humans, and this can make things confusing! To avoid giving dangerous or unhealthy vegetables to your tortoise, always research food using a tortoise-specific resource such as this website. Never assume that a good Vitamin K source for humans will be safe for a tortoise.
My top tip is that if you’re worried about your tortoise’s Vitamin K intake right now, start by adding a small amount of Green Beans, Dandelions (carefully washed to remove any pesticides), or Brussels Sprouts to their diet. These are all safe in moderation and provide enough Vitamin K1 to stave off a deficiency.
Let’s say half of one meal, once a week for four weeks. This will give them immediate dietary Vitamin K1 while giving you time to research their diet more thoroughly.
When to see a vet
If you see any of the symptoms of Vitamin K deficiency, book an appointment with a specialist reptile vet. This condition may be linked to other health problems or share symptoms with them, meaning blood analysis will be necessary to make a reliable diagnosis.
If a deficiency is present, it may not be as severe or life-threatening as Vitamin A deficiency for example. This is thanks to the helpful gut bacteria that I mention in the second section of this article.
Nonetheless, it will necessitate supervised supplementation from your vet. In some cases, this can be started at the clinic and continued by yourself at home.
After treatment, it’s important to ask your vet to help you review your animal’s diet, but also to carry out your own research.
During recovery, remember that the animal is in a weakened state, and that deficiencies make reptiles more vulnerable to diseases. To avoid other illnesses setting in, pay extra attention to the hygiene and temperature of the enclosure.
Wrapping up
Fortunately, Vitamin K deficiency is easier to prevent, and often less severe than others. All you have to do is make the right foods available to your pet.
Don’t be overwhelmed when planning your pet turtle or tortoise diet. With a little research you are perfectly capable of providing a varied and balanced range of foods that will provide all the Vitamin K necessary.
As far as Vitamin K supplementation goes, none is necessary for tortoises with a good diet! The same thing goes for aquatic turtles that regularly eat high-quality turtle pellets.
When it comes to carnivorous turtles, supplementation once a month is a good idea. Don’t forget that this can either be fed to their prey or dusted onto it – whichever is easiest for you.
Always be aware that keeping records of what you feed your pet and when will be the best way of avoiding deficiencies of any kind. I know this sounds like a lot of effort, but it is worth it.
If you feel like a deficiency is already a problem, I do not recommend home treatment. This is purely down to the fact it can be so similar to other issues. Booking an appointment at the vets is definitely the right way to go.
As always, comment or get in touch for more help!