Levels less than 30 ng/ml are considered inadequate.

The global average of Vitamin D levels is reportedly 20 ng/ml, and this is considered a lev-el that reflects deficient levels.

Vitamin D is synthesized by the skin in response to sun exposure, then acts as a hormone regu-lating immunity, fertility, and bone health, among other things.

Underexposure to daytime sunshine can poorly affect our melatonin levels, which in turn dis-rupts our circadian rhythms, and thus our sleep/wake cycles.

Sunlight is the primary natural source of Vitamin D. Cow’s milk which has in the past been touted as a good source of Vitamin D, is a digestive challenge for many. This is due to several reasons including a large percentage of the global population being lactose intolerant.
If Vitamin D deficient, apart from a healthy exposure amount to sunlight, supplements are a much better source of Vitamin D than dairy.