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Can Tortoises Eat Spinach? [Are Oxalates In Spinach Toxic]

Can Tortoises Eat Spinach? [Are Oxalates In Spinach Toxic]

In this post we discuss we take a deeper look into whether it is safe to feed spinach to torts and the benefits and risks involved in doing so.

Can tortoise eat spinach?

Tortoises can eat spinach. However, tortoises should have spinach sparingly as it contains oxalic acids that prevent the absorption of calcium and can cause kidney stones in high levels. Additionally, spinach contains calcium oxalates that can also cause irritation in the mouth and throat of tortoises.

Offering a variety of food items to tortoises is one of the ways to ensure they have a balanced diet.

Can you feed tortoise spinach?

Given that tortoise is herbivorous, they depend on leafy greens and other plant materials to source their nutrients for maintaining their bodies.

Moreso, calcium is one of the most important minerals that every tortoise owner should make sure their tortoise gets in plenty since they need it for shell growth and bone development.

Tortoise uses a form of digestion known as fermentative digestion to obtain energy. Fermentative digestion involves protozoa, bacteria, and fungi that break down fiber into carbohydrate that serves as the energy source.

Therefore, it goes without saying that you should make sure your tortoise receives enough fiber in their diet, most of the leafy greens have a poor fiber content.

Which is why it is recommended they be fed in moderation.

Nutritional Value of Spinach for Tortoises

The table below shows the nutritional value of 100 grams of spinach. source

Total lipid (fat)0.39g
Carbohydrate, by difference3.63g
Calcium, Ca99mg
Phosphorus, P49mg
Sodium, Na1mg
Vitamin C28.1mg
Iron, Fe2.71mg
Magnesium, Mg79mg
Potassium, K558mg
Vitamin B-60.195mg
Vitamin A, RAE469µg
Carotene, beta5626µg
Vitamin E2.03mg
Vitamin K 482.9µg

Benefits of Feeding Spinach to Tortoises


Fiber is very important in the diet of a tortoise, in fact, experts advise that a high percentage of a tortoise diet should be composed of fiber.

Tortoise digestion system is controlled by protozoa, bacteria, and fungi that break down fiber into carbohydrate that serves as the energy source.

Feeding your tortoise a diet that has a poor fiber content wi result into loose feces.

Fiber should make up about 10-40% of the tortoise daily dry matter intake, with 18% to 28% being considered as the optimal daily fiber intake for tortoise.

Protein and Fats

Proteins and fats alos serve as a source of energy for tortoise but not as much as fiber does.

However, most leafy vegetable protein and fat content is quite low and therefore cannot serve as a source of protein and fats for your pet tortoise.

Spinach despite having proteins and fats, should not be treated as a source of these important nutrients for tortoise.

Experts recommend that fats and proteins should be limited to about less than 10 % for fats and between 15- 35% for proteins.

Calcium and Phosphorus

One of the most important minerals in the tortoise diet is calcium and phosphorus. Calcium plays a very important role in the growth and development of all reptiles.

Given that tortoises are shelled reptiles, they will need a high calcium concentration in their diet to promote the growth of their shell plus bones.

For tortoises to achieve optimal growth, which will include the development of a strong and aesthetically beautiful shell and skeleton in general, proper calcium and phosphorus content must be available in their diet.

Most vegetables have poor calcium to phosphorus ratio, which means that for young tortoises that are still forming their shells you ought to exercise a lot of care before choosing vegetables to feed them.

Always be conscious of the calcium-phosphorus content ensuring calcium is higher than phosphorus for feeds that you feed daily.

Any plant material that has a skewed calcium-phosphorus ratio with phosphorus content being higher than calcium should be fed moderately.

About three-fourths of the elements in the tortoise body are made of calcium and phosphorus with the other elements making up the remaining part of the body.

All these elements are crossly interrelated and the function of one depends on the availability of another.

Functions of calcium in tortoise body includes,

  • Assists in blood clotting
  • Acid-base balancing
  • Participates in  muscle growth, muscle contraction, and nerve transmission
  • Promotes the absorption of other minerals such as iron
  • Activation of some enzymes
  • Nutrients transmission

Functions of phosphorus in the tortoise body include

  • Controls most chemical reactions in the body
  • Controls utilization of fats, carbohydrates, and proteins
  • Promotes DNA transfer
  • Promotes skeletal growth, kidney health and

Compared to other minerals the absorption of calcium is quite inefficient, Its absorption is directly affected by two factors, Calcium availability in the diet and how much calcium the body needs.

When calcium is in excess it is usually excreted, some substances such as fat prevent its absorption as when they combine with the calcium they form compounds that cannot be absorbed in the body.

Other substances that affect absorption of calcium negatively include oxalates and phytic acid.

While calcium supplements should be supplemented, there is no need of supplementing phosphorus.

Vitamin D concentration in the tortoise body is also very important in relation to calcium absorption, you should therefore make sure that your pet gets enough vitamin D either from sunlight or from UVB light and supplementation.

The recommended calcium to phosphorus ratio is either 1:1 or 2:1 respectively.

Miscellaneous Trace Elements

Other minor minerals present in spinach that are important to tortoise include sodium, iron, magnesium, and manganese.


Water is very important for all reptiles whether desert dwellers or not. A supply of fresh clean water should always be available to your pet tortoise.

Another way to make sure your pet is well-hydrated is to offer food high in water content such as fruits for tortoises that eat fruits and veggies.

Spinach is among some of the veggies that have a high water content. Nonetheless, it should only be fed sparingly.


Despite the fact that the precise vitamin requirement among tortoises and their close relative’s turtles has not been precisely determined, you should always ensure they get enough vitamins on a daily basis.

Deficiency of some of these vitamins can lead to life-threatening health conditions.

Some vitamins such as vitamin D can be synthesized from the sun and is very important towards calcium absorption and bone formation.

Other vitamins can easily be synthesized from the kidney while others can be synthesized from the guts.

Below is a list of vitamins that can be are available in spinach and their benefits to tortoise.

Vitamin A

Vitamins A falls under the fat-soluble category of vitamins. Vitamin A should always be in the diet of your tortoise on a daily basis.

Especially for a young tortoise that is still developing, Vitamin A is very important in the development of the respiratory and immune system of the tortoise.

Signs of vitamin A deficiency include

  • Swelling and inflammation of the eyelids
  • Difficulty in breathing
  • The horny part of the mouth develops abnormally e.g distortion and overgrowth
  • horny skin layers thicken
  • weak immune system
  • limbs become swollen

Spinach has both vitamin A and its precursor beta carotene, while excess vitamin A can be dangerous to the tortoise as it is stored in the liver and can cause a condition called Hypervitaminosis A.

Beta carotene is better since the body converts it to vitamin A and the excess is excreted from the body.

Signs of Hypervitaminosis A include drying of the skin leading to redraw patches and abnormal bone development and enlargement of the liver.

Vitamin E

Vitamin E is also categorized as a fat-soluble vitamin. Signs of vitamin E deficiency include Innapetance, skin sloughing, incoordination, liver necrosis, tongue ulcers.

Vitamin K

Vitamin K just like the above-mentioned vitamins is a fat-soluble vitamin. Vitamin K is one of the vitamins that are synthesized from the guts of the tortoise.

If a tortoise is under probiotics medication it can suffer from vitamin K deficiency that can lead to spontaneous bleeding.

B vitamins

B vitamins are made of a group of vitamins that are water-soluble. The advantage of being water-soluble is the fact that they cannot cause toxicity to the tortoise since the excess is normally excreted.

Spinach contains the following B vitamins thiamin, niacin, and vitamin B-6. Despite being needed in trace amounts these vitamins are very crucial towards the health of the tortoise.

How to feed Spinach to tortoise

The best spinach is the ones you have sourced from your garden since you will be sure they do not have pesticides. Follow the following steps when preparing spinach for your pet tortoise.

  • Wash the spinach thoroughly
  • cut spinach into pieces depending on the size of your tortoise
  • Do not offer spinach placed on a sand substrate
  • Probably put it in your lawn if it is free from pesticides or chemicals
  • You can mix spinach with other veggies to provide a variety

Can Russian tortoises eat spinach?

Horsefield or Russian tortoises can eat spinach. However, due to the levels of oxalic acid, Russian tortoises should have spinach sparingly to avoid the formation of kidney stones plus mouth and throat irritation. Oxalic acid in spinach can also prevent the absorption of calcium.

Can sulcata tortoises eat spinach?

Sulcata tortoises can eat spinach. However, they should have spinach sparingly since it has high levels of oxalates that inhibit the absorption of calcium. Calcium oxalates in spinach can also cause mouth or throat irritation in high levels. A high fiber diet should take up the bulky part of a sulcata tortoise diet.

Related Questions

Can desert tortoises eat spinach? Yes, desert tortoises can eat spinach, but they should be fed spinach in moderation since spinach are high in oxalic acid. Oxalic acids impair the absorption of calcium that is very important in desert tortoise growth and development.

What vegetables can tortoises not eat? Tortoises should not eat frozen or canned vegetables, tortoises should also not eat oleander, chinaberry trees, tree tobacco and toadstools.


While spinach is good for tortoise, when fed in excess, it can cause life-threatening conditions such as metabolic bone diseases which is a disease caused by lack of enough calcium in the body.

The calcium to phosphorus ratio of spinach is within the recommended value, however, spinach has a high oxalic acid level that reacts with calcium to form calcium oxalates that prevent calcium from being absorbed into the tortoise body.

Always consult your vet before starting your tortoise on any new food, and exercise caution when feeding food known to have high oxalic acid or skewed calcium to phosphorus ratio that differs from 1:1 or 2:1. You might as well keep away from them altogether since there are tons of other plant materials that are safer for tortoises such as dandelion.