Less Vitamin D available to tissues
Less D in blood & Less D getting from the blood into tissues
Less D from the SUN
Outdoors less for many reasons, such as Air conditioning
Instructed to fear skin cancer from the sun
Less D from FOOD
Less D in chickens, eggs, pork (raised away from the sun)
Less D in fish (>50% of fish now are farmed)
Less D from skim dairy products
Less D due to Less cholesterol - which is required to generate Vitamin D from the sun
Less D due to Less Omega-3 in dairy, fish, etc - which decreases Vitamin D in tissues
Less D due to Less Magnesium in foods - which decreases Vitamin D in blood and tissues
Less D in tissues due to Glyphosate and Vitamin D - many studies (Roundup) increasing the CYP27A gene which destroys Vitamin D
Less D in subsequent generations due to Antibiotics and Vaccines
Antibiotics and Vaccines allow poor immune systems to be inherited.
Less D due to body restrictions
Obesity results in storing some vitamin D in fat, lowering the blood levels of vitamin D
5 genes can restrict Vitamin D in blood from getting to tissues
Some diseases (i.e. Breast Cancer ) have learned how to de-activate Vitamin D Receptor genes,
thus protecing itself by reducing the amount ot Vitamin D getting to tissues