Vitamin D | Calcifediol |25 dihydroxy vitamin D
Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and phosphorus, key elements for bone health. It also plays an important role in immune function and cell growth, among many other things. Your body makes vitamin D when your skin is exposed to sunlight. You can also get it from certain foods like fatty fish, fortified dairy products, and egg yolks, or from supplements.
Testing for Vitamin D Levels
- Blood test: This test item provides levels of calcifediol. Choose this option if you are looking for Calcitriol, 25-hydroxyvitamin D.
Normal Vitamin D Levels
- The Institute of Medicine suggests that an adequate or normal vitamin D levels are 20 nanograms per milliliter (50 nanomoles per liter) to 50 ng/mL (125 nmol/L), but this can vary between different health organizations. Functional medicine physicians encourage patients that normal levels of vitamin D are considered to be at or above 50ng/mL.
Key Benefits of Vitamin D
- Bone Health: Vitamin D helps the body use calcium and phosphorus to build and maintain strong bones and teeth. Deficiency can lead to conditions like rickets in children or osteoporosis in adults.
- Immune Function: Some research suggests that vitamin D benefits in regulating the immune system, potentially reducing the risk of autoimmune disorders and infections.
- Mental Health: Emerging studies suggest that vitamin D could have a role in mood regulation and might help to alleviate symptoms of depression.
- Heart Health: Low levels of vitamin D have been associated with an increased risk of heart disease, though more research is needed.
- Other Health Considerations: There are ongoing studies to determine the relationship between Vitamin D and diseases like diabetes, cancer, and multiple sclerosis.
Effect of Vitamin D on Methylation and Serotonin Receptor Sensitivity
Association of Low Vitamin D Methylation of DNA:
Vitamin D has been implicated in the regulation of epigenetic events, including DNA methylation. DNA methylation is a process that controls gene expression and can be influenced by various factors, including nutrition and exposure to certain environmental conditions.
Research has shown that vitamin D can affect DNA methylation patterns, particularly within genes associated with autoimmune diseases, cancers, and cardiovascular diseases. It is postulated that vitamin D influences the methylation process through the vitamin D receptor (VDR), which interacts with enzymes responsible for adding or removing methyl groups to the DNA molecule. However, the specific mechanisms and outcomes of these interactions are complex and not yet fully understood. Deficiency in vitamin D might affect normal methylation patterns, potentially contributing to disease development.
Vitamin D and Serotonin Receptor Activity:
Serotonin, a key neurotransmitter, plays an essential role in numerous biological processes, including mood regulation, social behavior, appetite, digestion, sleep, and memory. Vitamin D appears to influence serotonin synthesis and signal transduction.
Vitamin D can influence the production of serotonin by regulating the expression of tryptophan hydroxylase 2 (TPH2), an enzyme involved in the synthesis of serotonin in the brain. When vitamin D binds to its receptor (VDR), it may promote the transcription of the gene for TPH2, thereby increasing the synthesis of serotonin.
Furthermore, vitamin D might play a role in the function of serotonin receptors. Some research suggests that vitamin D may help to upregulate serotonin receptor expression and enhance serotonin-mediated responses, though more research is needed to fully understand these mechanisms.
The relationship between vitamin D, DNA methylation, and serotonin receptor activity underscores the complexity of vitamin D's roles in the body and its potential relevance to conditions like depression, schizophrenia, cardiovascular disease, and certain cancers. It's important to note, though, that while these relationships are supported by some research, they are still areas of active study and not yet fully understood.
Why Doctors Recommend Ordering Calcifediol vs Calcitriol:
When testing for vitamin D levels in the body, healthcare providers typically measure the amount of 25-hydroxyvitamin D, also known as calcifediol, rather than 1,25-dihydroxyvitamin D or calcitriol, the active form of the vitamin. This is due to several reasons:
- Higher Concentration: Calcifediol is present in the blood at higher concentrations than calcitriol.
- Longer Half-Life: Calcifediol has a longer half-life in the body than calcitriol (approximately 2 weeks compared to 4 to 6 hours for calcitriol). Therefore, calcifediol levels provide a more stable and accurate reflection of vitamin D status over time.
- Regulatory Mechanisms: The kidneys tightly control the conversion of calcifediol to calcitriol as part of the body's regulation of calcium and phosphorus. Even if a person is deficient in vitamin D, their calcitriol levels could be normal or even elevated due to these regulatory mechanisms. Therefore, calcitriol levels are not a reliable indicator of total body vitamin D status.
It's important to note that while measuring calcifediol is the standard method of assessing vitamin D status, it does not provide a measure of all aspects of vitamin D health, such as its conversion to its active form or its effects on cellular signaling and gene expression. Therefore, a comprehensive evaluation of a person's health and other tests might be necessary for a complete understanding of a person's health status.
Causes of Vitamin D Deficiency
Limited Exposure to Sunlight:
- Due to lifestyle (indoors most of the time, wearing clothing that covers most of the skin)
- Living in northern latitudes where there is less sun exposure, especially in winter.
- Using sunscreen, which blocks the sun's rays that the skin needs to produce vitamin D.
Dietary Factors:
- Following a strict vegan diet. Most natural sources of vitamin D are animal-based.
- Malabsorption issues due to conditions like celiac disease, Crohn’s disease, and cystic fibrosis, which affect the intestine's ability to absorb fat (vitamin D is a fat-soluble vitamin).
Health Conditions:
- Obesity: Fat cells extract vitamin D from the blood, altering its release into circulation.
- Kidney and liver diseases: These conditions can affect the ability to convert vitamin D into its active form.
- Hyperparathyroidism: Overactive parathyroid glands can cause excessive calcium absorption, which can result in vitamin D deficiency.
Age:
- Older people have thinner skin, which may result in less vitamin D being produced when they're exposed to sunlight.
- The ability to convert vitamin D into its active form decreases with age.
Genetics:
- Variations in genes related to vitamin D metabolism (e.g., GC genes, which produce a vitamin D-binding protein, or CYP2R1, CYP27B1, and CYP24A1 genes, which are involved in the conversion of vitamin D into its active form).
Other Factors:
- Certain medications can alter vitamin D metabolism, such as anticonvulsants, glucocorticoids, antifungals, and HIV/AIDS medicines.
- Infections, especially those that result in prolonged inflammation, might influence vitamin D status. Chronic infections could lead to lower vitamin D levels due to increased inflammation and metabolic demand.
- Chronic stress and high cortisol levels may also potentially impact vitamin D levels
Vitamin D Deficiency and Treatment Options
- Symptoms of Deficiency: Symptoms can include fatigue, bone pain, muscle weakness, mood changes, and frequent illness.
- Treatment: Treatment typically involves increasing sun exposure, altering diet, or taking supplements. Dosages will depend on the severity of the deficiency, age, weight, and other individual factors.