Vitamin D Benefits and How Can I Test for Its Deficiency?
You probably heard about vitamin D and asked yourself—“What Vitamin D is good for?” or "What are the signs of vitamin D deficiency?" Historically Vitamin D was known as a nutrient your body needs for building and maintaining healthy bones. This is still correct as your body can only absorb calcium, the primary part of bones, in the presence of Vitamin D. In recent years, Vitamin D has become a wellness factor because it also regulates many other functions in your body, like anti-inflammatory and antioxidant agents. It also has other cellular functions and neuroprotective properties that support your immune health, muscle function, and brain cell activity. Although more studies are needed to conclude full scientific evidence, a high correlation of lack of Vitamin D was shown in multiple diseases and disorders, including Cancer, Cognitive Health, Multiple Sclerosis, Osteomalacia, Osteoporosis, Psoriasis, and Rickets.
The main source of Vitamin D in your body is converting a chemical called Calcifediol in your skin by direct sunlight exposure into the active form of the vitamin Calcitriol (also known as 1,25-dihydroxycholecalciferol, or 25(OH)D). The second conversion (in form of hydroxylation) occurs primarily in your kidney and forms the physiologically active 1,25-dihydroxyvitamin D, or 1,25(OH)2D, also called Calcitriol. However, in contrast to 25(OH)D, circulating 1,25(OH)2D is generally not a good indicator of vitamin D status because it has a short half-life (the time it takes one-half of a substance to degrade) measured in hours, and its levels in the blood are tightly regulated by parathyroid hormone, calcium, and phosphate (e.g. you'd need to measure also calcium and phosphate to know if your vit D is low). On the other hand levels of 1,25(OH)2D do not typically decrease until vitamin D deficiency is severe1. Most vitamin D tests are measuring the 25(OH)D form.
During periods of sunlight, Vitamin D is stored in fat and then released when sunlight is not available. Vitamin D isn't naturally found in many foods other than fatty fish such as salmon, mackerel, and sardines. Vitamin D is also available in some plants like mushrooms. That is the reason it is added to fortified milk and fortified cereal. The amount of vitamin D your skin makes depends on the time of day, season, latitude, and skin pigmentation. In some high latitude areas, Vitamin D production might be completely absent during the wintertime. On the other hand, an indoor lifestyle and sunscreen, which is important to prevent skin cancer, also decrease Vitamin D production. With so many benefits, disease prevention, and a modern lifestyle, it is important to check your Vitamin D level to ensure that you do not have a Vitamin D deficiency.
There are different forms of Vitamin D, including ergocalciferol (Vitamin D2) and cholecalciferol (vitamin D3). Vitamin D2 and D3 are slightly different in their chemical structures. However, they are both absorbed well in your gut. Vitamin D2 is derived from plant sources, and Vitamin D3 comes from animal sources or exposure to sunlight. Vitamin D home test either alone or as part of their wellness & inflammation panels is available online from multiple lab providers.
To avoid Vitamin D deficiency, it is recommended to take vitamin D supplements. You can either take a multivitamin with Vitamin D or just Vitamin D. The recommended daily amount of Vitamin D is 400 international units (IU) for babies (newborns up to age 12 months), 600 IU for people ages 1 to 70 years, and 800 IU for people over 70 years. In general, Vitamin D is considered safe. However, taking too much vitamin D in the form of supplements can have side effects. Children at age 9 years and older, adults, pregnant, and breastfeeding women should not take more than 4,000 IU a day of vitamin D supplements.
The cost of vitamin D test is in the range of $40.0-99.0; Do you know what Vitamin D is good for?