Vitamin D functions as a prohormone responsible for enhancing the absorption of calcium, iron, magnesium, phosphate and zinc.
Before supplementing Vitamin D3, both levels of Vitamin D must be tested via blood work. The 2 types needed are:
*25 Hydroxyvitamin D (Calcidiol) is the storage form that is commonly measured in annual blood work.
*1,25 Dihydroxyvitamin D (Calcitriol) is the active form and can also be measured in blood.
If your D 1,25 is low, you can safely take 10,000 UL of vitamin D3 along with K2 with a fatty meal for better absorption. Magnesium is important too. Magnesium needs to be taken away from D supplements and work up to 5mg of magnesium per pound of body weight as tolerated.
*Make sure to be off Vitamin D supplements 5 days prior to labs.
K2 recommendations: 150mcg for 5,000 D3, and 250mcg of K2 for higher D3.
You want your calcitriol to be no higher than top of range and no more than double your storage D (1.5x is better) putting regular D at a max of about 50 to be healthy. Elevated active D pulls calcium out of your food and bones and into your blood. Not only does this weaken bones but it elevates serum calcium which can accumulate in joints and muscles, causing inflammation and pain. If Active is too high and Storage is too low it will deplete calcium.
If 1,25/25 ratio is >2, do NOT supplement.
Example: 1,25 = 89.5 (high)
25 = 25.7 (below range) 89.5/25.7 = 3.48 Do not supplement.
Before supplementing Vitamin D3, have both levels of Vitamin D done with blood work. Your storage level may be 30 ng/mL, but your active Vitamin D may be optimal @ 50-75 pg/mL.
*Always look for a balance between the two.
You can order both Vitamin D tests here:
In the United States:
ultawellness.com
mymedlabs.com
In the UK:
medichecks.com
Here is another site with a wealth of info on Vitamin D: https://www.ncbi.nlm.nih.gov/pubmed/28768407?fbclid=IwAR2DCM2dGPTIzYruQ633kDn44fPsS8ROEmxQu9JI7ZdXVkalN3Qrdda7mak