Nature intended for us to get vitamin D from exposure to sunlight, but absorption is blocked by sunscreen, and the darker our skin complexion, the more Vitamin D we need. We need bare-skin sun exposure for 15-20 minutes a day and most of us don't get that, especially those of us living north of 37 degrees latitude (yes, that's you Seattle!). Additionally, we don't eat enough D-rich foods, which include egg yolk, cod liver oil, shiitake mushrooms, and wild salmon. Fortified milk/dairy is not the best source because you would need several cups every day. For anyone intolerant of dairy products and for vegans, this food category is off limits.
Vitamin D is not only powerful, it's vital for good health. Although it's called a vitamin, D is actually a fat-soluble steroid hormone that acts as a catalyst for processes that protect our cells. Every tissue in the body needs vitamin D, yet a large percentage of the world's population is deficient, or borderline deficient, in this critical hormone. Vitamin D deficiency is associated with higher risk of bacterial infections and viruses, so if you want to protect yourself from getting the latest cold or flu, it’s important to keep your levels up. In addition to common bugs, even a mild D deficiency can contribute to chronic and autoimmune diseases such diabetes, cardiovascular disease, depression, cancer (including ovarian, colon, and breast), multiple sclerosis, and psoriasis.
The best way to help the body establish optimal levels of vitamin D if you can’t get it from the sun all year round, is to take a high quality supplement. But what most people don’t know is that vitamin D should always be taken in combination with vitamin K. Vitamin D has long been associated with bone health because it assists with calcium absorption, but it also works to regulate calcium in the bloodstream, pulling it from bone if levels in the blood get too low. The vitamin K acts as a shuttle to make sure that calcium actually goes into your bones, and prevents calcification of soft tissues like your kidneys or blood vessels.
The upper recommended daily allowance of vitamin D is 2000iu, but this recommended dosage is not taking into account wether or not the D is accompanied by vitamin K. The risk of taking high doses of vitamin D without K is that it can cause a condition called hypercalcemia, or toxic levels of calcium in the blood. Taking D without K can also increase risk of osteoporosis and hip fractures.
The recommended blood level of vitamin D (above 25 nmol/L) was established to protect people from bone disease (rickets and osteomalacia). From the natural medicine perspective (and emerging scientific data), that threshold is too low to protect against serious illness or to promote optimal health. Depending on the individual, many holistic physicians identify 45-90 nmol/L as the ideal vitamin D blood level for disease prevention, but many of the doctors I work closely with prefer to see levels between 75-100 nmol/L.
Age, gender, diet, stress level, and lifestyle factors all affect absorption of vitamin D. Taking 2000 iu of vitamin D and 90 mcg of K daily is considered very safe, but if you want to be sure you’re taking the right dosage, ask your holistic physician to order a blood test to help ensure you take the appropriate amount and form of vitamin D. Follow-up testing tracks improvement in your levels and health conditions, and your practitioner can then adjust your supplement dose accordingly. Vitamin D and K are fat-soluble so be sure to take it with food, ideally at breakfast.
We should all practice safe sun, but getting some good old fashioned real vitamin D from the sun is the ideal and most effective way to get your D. But if you’re like me and live North of about San Francisco or don’t get 15 minutes of real sun exposure each week, supplementing is a good idea.