Vitamins are required to sustain normal cell function, growth and development, and thus are essential to our very beings. One that has been receiving much deserved attention of late is vitamin D. Touted as everything from a cancer-crusher to a bone-builder, we wanted to find out how much in its various forms we actually need, and just how to get it.
Vitamin D is a fat-soluble “pro hormone” – a substance that usually has little hormonal activity by itself, but that the body can turn into hormones. There are two forms of vitamin D that are essential to humans:
◗ VITAMIN D2 made by plants
◗ VITAMIN D3 made by our skin when exposed to sunlight.
DEFICIENCY DANGERS Untreated vitamin D deficiency puts you at a higher risk for osteomalacia, dental cavities, osteoporosis, and thyroid conditions, and in children it can cause rickets, a bone weakening disease. Symptoms include bone pain and muscle weakness, and require a prompt visit to the doctor.
Based on the most recent study, the recommended daily allowance (RDA) for vitamin D is 600 IU for most people. This includes children and pregnant women. For those over the age of 70, a higher intake of 800IU is recommended.
what it does
NO BONES ABOUT IT: The body cannot metabolize and absorb calcium without vitamin D. We need it in order to form the hormone calcitriol, which facilitates the absorption of calcium from our food into our bloodstream. If the body does not have enough of this hormone, it will start pulling from the calcium stores in our bones, reducing bone density and ultimately resulting in osteoporosis. Vitamin D also aids neuromuscular and immune function, and reduces inflammation.
D-LINK AND CANCER: While further studies are needed, early research has shown a link between people with higher vitamin D intakes and a decreased risk of specific diseases, including prostate, colorectal, and lung cancers. A 2014 study at the University of Washington published in Cancer Research indicates that vitamin D reduces inflammation and subsequent colon cancer in mice. All the more reason to get your D!
how to get enough
HERE COMES THE SUN: Living in the Sunshine State may provide an adequate amount of vitamin D3 for some, but sun exposure opens us up to the risk of skin cancer and by itself is not enough to keep us immune to vitamin D deficiency. The only way to be certain you are getting enough is through a blood test from your doctor. According to the National Institutes of Health, your vitamin D blood level should range from 25-50 nanograms per milliliter, with most people’s requirements falling on the higher side (although more than 50 nanograms per milliliter may have adverse effects).
While regular checkups cover blood work for some nutrients, most don’t include the test for vitamin D (called 25(OH)D or 25-hydroxyvitamin D), so ask for it specifically.
TAKE A WALK ON THE SUNNY SIDE: Recent recommendations encourage ten minutes of unprotected sun exposure at least three times a week. Darker pigmented skin may require more exposure, as greater amounts of melanin reduce the skin’s ability to produce vitamin D from sunlight. Take caution and avoid the hours between 10:00 a.m. and 3:00 p.m.
While naturally occurring sources are more easily absorbed by the body, fortified foods can help us reach our daily RDA. Milk, orange juice, and some cereals are fortified with D – check your labels, and always look for whole grain, organic, low-sugar options. Try fortified almond milk or organic Greek yogurt.
For those with D deficiencies, supplements provide an easy remedy. D2, or ergocalciferol, is synthetically made from fungi and yeasts and sold in capsule form. D3, or cholecalciferol, can also be made synthetically in a process similar to that of D2 and purchased over the counter.
Try these: LifeGive Sun-D (vegan; sourced from mushrooms) and Garden of Life Vitamin Code Raw D3 (vegetarian; sourced from yeast). For optimal absorption take your fat-soluble D supplements with a good source of fatty acids, like a handful of walnuts or a few slices of avocado.
d-rich and delish
Foods rich in vitamin D include:
EGGS: The D is in the yolk – one yolk contains about 40 IUs – so make sure you’re not just eating egg whites. A cup of hardboiled eggs contains approximately 118 IUs.
MUSHROOMS: Look for brands grown in ultraviolet light to increase vitamin D production, as opposed to those grown in the dark. Dole’s portabella mushrooms will provide you with 400 IUs per 3-ounce serving (about 1 cup diced mushrooms).
FATTY FISH: Salmon is a great source (wild salmon providing even more than farmed), with half a filet of sockeye salmon containing more than 1400 IU – double the amount most people need in a day, and an added bonus of health omega-3 fatty acids. Trout weighs in at 539 IUs per fillet, while a serving of two sardines will give you 46 IUs.
COD LIVER OIL: A tablespoon provides 1,400 IUs – more than double the RDA, in addition to being a great source of vitamin A and omega-3 fats.
BEEF LIVER: A 3.5-ounce serving of cooked beef liver contains about 50 IUs of D, and a side of vitamin A, iron, and protein.