What is Vitamin D?

Vitamin D3 has recently become a popular supplement, second only to multivitamins among Americans. Bio-Tech’s vitamin D has been endorsed by prestigious organizations such as Grassroots Health and The Vitamin D council, as well as being used for numerous studies across the nation. Bio-Tech M&D carries vitamin D3 in strengths of 2,000 IU [D3-2], 5,000 IU [D3-5], and 10,000 IU [D3-K2] for daily use, Bio-Tech M&D also carries the only vitamin D formula endorsed by the Vitamin D Council, our D3Plus. But just want is the “sunshine” vitamin and why should it become a part of your daily routine?

Vitamin D is a fat-soluble vitamin known primarily for its role in bone health and in calcium and phosphate balance in the body, though new research is constantly revealing new benefits and uses within the human body. It is distributed as a dietary supplement in two forms, ergocalciferol (D2) and cholecalciferol (D3). While ergocalciferol is plant derived and less bioavailable, cholecalciferol is the form of vitamin D produced in human skin when exposed to sunlight, its more in the human body when taken as a supplement (1,2,3) and what Bio-Tech M&D uses in our supplements.

Vitamin Dis passively absorbed in the lower part of the small intestine, and though many believe taking the supplement with meals containing fat increases its absorption, studies have shown that is not always the case. In general, it does not matter WHEN you take Vitamin D, but rather that you take enough.

Vitamin D Deficiency

As mentioned above, sunlight stimulates the production of vitamin D within the body, and in an ideal world, this would be enough. In our ever-changing culture the individual’s exposure to sunlight is becoming increasingly insufficient, whether through more sedentary indoor based lifestyles or worsening air conditions. This leads to an increase of vitamin D deficiency, with more than three million cases in the United States per year. Other factors affecting the production of vitamin D are the time of day, location, skin color, and certain medications that interfere with its absorption and utilization in the body. The most commonly seen diseases of severe vitamin D deficiency are osteomalacia and rickets, though a growing body of evidence suggest a myriad of additional resulting health concerns. The Vitamin D Council defines vitamin D deficiency, or hypovitaminosis D, as having a serum level less than 30 ng/mL, and vitamin D insufficiency as less than 40 ng/mL.

Risk Factors for Vitamin D Deficiency

According to the NIH Office of Dietary Supplements

  • Breastfed Infants
  • Older Adults
  • Limited Sun Exposure
  • Dark Skin
  • Inflammatory bowel disease and other conditions causing fat malabsorption
  • Obesity
  • Gastric Bypass surgery

Vitamin D and Heart Health

Increasing studies over the past several years have linked vitamin D to cardiovascular health and wellness (4). Vitamin D Receptors have been found in arterial wall cells, cardiomyocytes, and immune cells, and the products of vitamin D receptor activation in these cells seem to play a role in inflammation, thrombosis, and the renin-angiotensin systems, which are all vital to cardiovascular function (5).*

Vitamin D and Bone Health

According to the National Institute of Health (NIH) in 2010, osteoporosis affects more than 40 million adults in the US alone. This disease which is characterized by low mass and increased fragility of bone is an effect of long-term calcium and vitamin D deficiency (6). Vitamin D is well known to promote calcium absorption and balance in the body, so is a vital factor in bone health and prevention of osteoporosis. A recent study showed a marked increase in vitamin D levels and bone mineral density in 52 men and women upon supplementation of vitamin D (7).

Vitamin D and Immune Health

Vitamin D Receptors can be found on numerous cells involved in immune activity, with vitamin D being a major regulator in their growth and function (8). Research has found that sufficient vitamin D has a positive effect on the expression of many genes involved in the immune response (9).*

Vitamin D and Blood Sugar Balance

There are many regulatory hormones within the human body, one of which is insulin. Insulin is secreted by β cells within the pancreas and works with the hormone glucagon to maintain blood sugar balance. Insulin resistance occurs when normal levels of insulin achieved a weakened response, decreasing the ability of this hormone to control blood sugar levels (10). Not only is vitamin D believed to stimulate insulin secretion, but it has also been associated with decreased insulin resistance and improved glucose balance (11Ϯ, 8; 12; 13).*

Vitamin D and Breastfeeding

The NIH has identified breastfed infants as being at risk for insufficiency due to low concentration of vitamin D in human milk. Recent studies, however, have shown that mothers supplementing with sufficient doses of vitamin D provide a greater concentration in their breast milk, resulting in sufficiency in the infant (14Ϯ).*


  1. J Clin Endocrinol Metab; 2008; 93(8):3015-3020.
  2. J Clin Endocrinol Metab. 2011; 96(4):981-988.
  3. Nephron. 2015; 130:99-104.
  4. Journal of Diabetes Research. 2013.
  5. Circulation Research. 2014.
  6. NIH, 10 Nov. 2014. Web. 20 Aug. 2015.
  7. Calcified Tissue International. 2013; 93(1):69-77.
  8. Trends Endocrinol Metab. 2010; 21(6):375-384.
  9. PLOS. 2013.
  10. Clin Biochem Rev. 2005; 26:19-39.
  11. Int J Endoncrinol Metab. 2015; 13(1).Ϯ
  12. Diabetes Care. 2010; 33(6):1379-1381.
  13. Research Reviews. 2009; 22:82-92.
  14. Mayo Clinic Proc. 2013; 88(12):1378-1387.Ϯ

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Ϯ The vitamin D3 supplements used in these studies were donated by Bio-Tech Pharmacal. Bio-Tech’s D3 has been chosen by researchers for use in more than 50 studies across the nation.