What are vitamins?
Vitamins are essential nutrients that animals' bodies require in small quantities to grow and develop normally. Different species of animals need different types and amounts of vitamins. Each of the 13 different vitamins plays a specific role in the body of each species. People require different amounts of each of the different types of vitamins to stay healthy.
What are the different kinds of vitamins?
The two primary classifications of vitamins are fat-soluble vitamins and water-soluble vitamins.
Fat-soluble vitamins are stored in the liver and fatty tissues in the body if you consume more of these vitamins than the body needs immediately for health. They can be stored in the body for days to months. The fat-soluble vitamins include:
- Vitamin A
- Vitamin D
- Vitamin E
- Vitamin K
Water-soluble vitamins do not stay in the body for long and cannot be stored. Water-soluble vitamins dissolve in water and are eliminated in urine if consumed in greater quantities than what is needed immediately for optimal health. The water-soluble vitamins include:
- Vitamin C
- All the B vitamins
- Thiamin (vitamin B1)
- Riboflavin (vitamin B2)
- Niacin (vitamin B3)
- Pantothenic acid
- Vitamin B6
- Biotin (vitamin B7)
- Folate and folic acid
- Vitamin B12
What is vitamin D?
Vitamin D is a type of nutrient that humans consume and a hormone that the human body makes. Vitamin D is a fat-soluble vitamin that is essential for health that comes in two forms, D2 and D3. You can get vitamin D by eating certain animal foods, foods that have been fortified with vitamin D, or by taking supplements that contain vitamin D2. The human body can also make vitamin D when bare skin is exposed to sunlight (vitamin D3).
Can a person have too much vitamin D (toxicity)?
Vitamin D is stored in the liver and fatty tissues in the body. While some foods have vitamin D naturally in them, people are still typically not able to get enough vitamin D for optimal health by eating these foods alone. Also, while the body makes vitamin D when bare skin is exposed to sunlight, too much sun exposure results in too much heat on the skin, preventing vitamin D from forming.Therefore, typically someone who has too much vitamin D in their system has taken an excessive amount of supplements high in vitamin D.
If too much vitamin D is consumed and stored, it can build-up to levels that are not ideal for health. Symptoms of too much vitamin D (toxicity) include:
- Irregular heartbeat
- Anorexia
- Weight loss
Excess vitamin D intake may also lead to increased blood levels of calcium, which can cause hardening of blood vessels and tissues and potentially lead to damage to the heart and kidneys.
What are the signs, symptoms, and possible causes of too little vitamin D (deficiency)?
If vitamin D levels remain low (deficient) for too long, health conditions may develop. Individuals whose bodies are not able to absorb enough vitamin D are also likely to not absorb enough calcium and phosphorus.
Infants and children with low vitamin D levels may experience soft bones and skeletal changes (deformities) because their bones cannot harden during growth and development. This condition is called rickets.
Adults with weak and softened bones may develop osteomalacia, which is able to be treated and reversed with supplementation. Osteomalacia is different from osteoporosis. While osteomalacia is a softening of the bones, osteoporosis is a condition associated with the body losing too much bone and making too little bone (bone deterioration), resulting in porous and brittle bones. Osteoporosis cannot be reversed with treatment and is a condition often associated with old age.
A vitamin D deficiency may occur from a lack of vitamin D in the diet or too little exposure of the bare skin to the sun. Vitamin D deficiency may also be a byproduct of certain health conditions in which the body has difficulty absorbing enough vitamin D for various reasons. Since vitamin D is stored in fatty tissues in the body, people who are living with Inflammatory Bowel Disease (Crohn's disease or Ulcerative colitis) or other conditions that result in difficulty for the body to absorb fat are also more likely to be vitamin D deficient. Also, obese people tend to have difficulty accessing the vitamin D stored in their fat cells, but blood levels of vitamin D typically rise when an obese person loses body fat. In addition, because the upper part of the intestine is where vitamin D is absorbed if it has been removed for gastric bypass surgery or to remove a blockage or cancerous tumor, vitamin D will not be able to be readily absorbed by the body, which would likely result in a deficiency. Certain kidney and liver conditions can also impact vitamin D levels because they reduce the amount of an enzyme needed to change vitamin D to a form that is used in the body. Further, people who have little exposure to sunlight either due to lack of time spent outdoors or living in an area with a rainy, gray climate may have low vitamin D levels due to lack of sunshine exposure.
How do you get vitamin D?
You can get vitamin D when you:
- Expose your bare skin to sunlight
- Eat foods that are natural sources of vitamin D
- Consume foods or beverages that have vitamin D added to them
- Take supplements that contain vitamin D
What foods are high in vitamin D?
Certain animal foods are rich sources of vitamin D, including:
- Egg yolks
- Saltwater fish (salmon, swordfish, tuna, sardines)
- Cod liver oil
- Beef liver
Vitamin D is also added to some other foods, such as milk and cereal. This is called fortification.
Where else can you get vitamin D other than food sources?
While some foods contain vitamin D, you are not likely to get enough vitamin D for optimal health from food sources alone. The human body also produces vitamin D when bare, unprotected skin is exposed to sunlight. Consuming vitamin D supplements is another way to get vitamin D.
What other nutrients are impacted when vitamin D intake is too low?
Vitamin D plays an important role in your body's ability to absorb and retain calcium and phosphorus. Hence, if your vitamin D levels are low for a prolonged period of time, this may impact your levels of these other nutrients as well. Both calcium and phosphorus are important for building bone, so having a prolonged low vitamin D level may ultimately impact bone health.
What body systems need vitamin D to function optimally?
Your body needs vitamin D to support the absorption and retention of calcium and phosphorus, which are both key to bone health. Vitamin D also can play a role in controlling inflammation in the body, reducing cancer cell growth, and helping the body control infections.
How do I know if the vitamin D test is a good fit for me?
If you have a health condition such as Crohn's disease, ulcerative colitis, or cystic fibrosis, or if you have had part of your small intestine removed, your body's ability to absorb vitamin D may be reduced. If you live in an area where the climate includes extended periods of rain and gray skies, such as the Pacific Northwest, your body may not be exposed to as much sunlight as is ideal for healthy vitamin D production.
Signs of low vitamin D levels in adults may include:
- Fatigue
- Bone pain
- Muscle weakness
- Muscle aches
- Muscle cramps
- Mood changes, like depression.
How will my at home vitamin D test be conducted?
The vitamin D test is a simple finger prick test. You will be mailed a sample collection kit that contains a simple device that will prick your fingertip. You will then collect a few small drops of blood on the collection card and mail it to the lab in the postage-paid return shipping materials included with your collection kit.
How will I access my results?
You will be notified by email or text as soon as the lab has finished analyzing your sample. You will be given a link to connect with your secure Patient Portal. After you log in with your secure password, you will be able to access your lab report and supporting educational materials.
What will my at home Vitamin D test results show?
Your body changes vitamin D2 (from food sources) and vitamin D3 (from sunshine) into a form of vitamin D called 25 hydroxyvitamin D, also known as 25(OH)D. This vitamin D test measures the level of 25(OH)D in your blood. Your results will report your vitamin D level, as well as compare them to the optimal vitamin D range for someone of the same gender at birth and of a similar age - reporting if your levels are below the recommended range, normal, or above the recommended range.
Will my results tell me what to do about my vitamin D levels?
Your Vitamin D test results will include educational information about vitamin D, including how you may be able to increase or decrease your vitamin D levels through lifestyle changes. Your results will also include guidelines about sharing the report with your physician to possibly further explore the possible cause, if your vitamin D levels are too low (deficiency) or too high (toxicity) for optimal health.
