What is Vitamin D?
Vitamin is D is actually considered to be a hormone that the body makes by the action of sunlight on the skin. How cool is that? However, with the decrease in the amount of time we spends outdoors, due to our office-style jobs, there has been a dramatic rise in the number of Vitamin D deficiencies in the US. Theories have proposed the decreased conversion in the body could be connected to estrogen and magnesium deficiency as well as the lack of the trace mineral Boron, which plays a role in conversion. Therefore, having enough trace minerals in the body to support vitamins like D are extremely important.
Functions and Benefits
The major role of vitamin D is to maintain normal blood levels of calcium and phosphorous. It helps the body absorb calcium, which forms and maintains strong bones. Vitamin D also aids immune support, so if you are prone to illness or colds and flus, you may want to have your levels checked. The best part about Vitamin D is the body can actually make its own when the skin is exposed to sunlight.
Vitamin D deficiency can result in rickets in children and osteomalacia in adults. These two conditions are characterized by an inability to calcify the bone matrix. Other indications for supplementation include tiredness, aches and pains, osteoporosis, cancer (breast and colon), heart disease, autoimmune conditions, frequent illnesses/infections and insulin resistance. The following people are more likely to be lacking in Vitamin D:
- People with darker skin. The darker the complexion, the more sun you need to get the same amount of vitamin D as a fair-skinned person
- People who spend a lot of time indoors during the day
- If you wear sunscreen or if your skin is covered in clothes
- Older people since they have thinner skin, which may mean they can’t produce as much Vitamin D
- People that live in the North of the U.S. or Canada because there are fewer hours of sunlight as you get further away from the equator
- Infants that are breastfed from a mother who is Vitamin D deficient
- Pregnant women
- People who are overweight (obese)
Natural Sources of Vitamin D
The sun is one of the best forms of Vitamin D. Making it a goal to get 15-20 minutes of sunlight a day is recommended. Food sources of vitamin D include: cod liver oil, wild sardines and salmon, egg yolks, butter, pastured beef (beef liver), leafy greens and Swiss cheese. Animal forms are best as they are already synthesized and converted. Always choose organic, pastured meats and wild sources of fish.
The ideal intake of Vitamin D is now 600 IU in the D3 form (D3=cholecalciferol). Some experts recommend 4,000-10,000 IU (100 IU = 2.5 mcg). D3 is available in capsules, tablets, and liquid. The Vitamin D Council recommends 5,000 IU per day for adults, 1,000 IU/day per 25lbs of body weight for children and 1,000 IU/day for infants. Research shows that vitamin D3 is the better type of vitamin D compared to vitamin D2. It is recommended to take your Vitamin D3 with some kind of fat, such as avocado or olive oil, as this ensures better absorption.
How do I know if I am Vitamin D deficient?
You may ask your doctor for a vitamin D test – 25(OH)D. This blood test tells you whether you are getting enough vitamin D. You may also order this test from a private lab, which allows you to bypass your Doctor: mymedlab.com, healthcheckusa.com, and privatelabs.com. A more convenient option is to get an in-home test. You may order these from ZRT Labs (zrtlab.com), City Assays (based in the UK-$48) and New Century Diagnostics. The in-home test simply requires pricking your finger to take a small blood sample and sending it in to the lab for testing. According to the Vitamin D Council, 40-80 ng/ml is the sufficient range for healthy vitamin D levels and 50 ng/ml is the ideal level in which to aim.
What do my results mean?
The Vitamin D Council has a very handy chart to interpret your results. You may find this information here.
Murray, M. (2005). The Encyclopedia of Healing Foods. NY: Atria Books
Vitamin D Council. (2003). What is Vitamin D? Retrieved from https://www.vitamindcouncil.org/about-vitamin-d/what-is-vitamin-d/
Hollis, Bruce W., & Wagner, Carol L., (2006) CMAJ. Nutritional Vitamin D. Retrieved from http://www.cmaj.ca/content/174/9/1287.figures-only