Vitamin D

Essential Micronutrient

OVERVIEW

Summary

Besides enhancing both immune and thyroid function, Vitamin D also delivers calcium and other vitamins and minerals to our bones, teeth, and joints. And it doesn’t stop there… it also aids in the absorption and functioning of these nutrients to help ensure proper support for their on-going strength.

Other names for Vitamin D

provitamin D, Vitamin D2 (ergocalciferol), calciferol, Vitamin D3 (cholecalciferol), Calcitriol (prescription drug form of Vitamin D), the “sunshine” vitamin

Where to find Vitamin D

Vitamin D is manufactured in the human body with help from sunlight, but it’s also found in shark and cod liver oil, fatty salt-water fish, butter, and egg yolks.

Note: Foods that contain high amounts of Vitamin D also contain high amounts of fat.

Popup: Foods highest in Vitamin D

Daily Value

The Daily Value for Vitamin D is 400 IU.

PERFORMANCE BENEFITS

Why athletes use Vitamin D

Supplementation of Vitamin D is becoming more common among athletes to decrease the risk of trauma-induced arthritis. Also, athletes who fear their D levels might be low because of low fat intakes find that a supplemental form is preferred.

Ways that Vitamin D can enhance Muscle Gain & Recovery:
  • Inhibit muscle weakness by stimulating mineral absorption into muscles
  • Ensure optimal joint function and prevent breakdown by aiding mineral absorption
Ways that Vitamin D can enhance Longevity:
  • Enhance immune function by aiding the delivery and absorption of nutrients

HEALTH BENEFITS

Signs of Vitamin D deficiency

Deficiency of Vitamin D has been linked to:

  • Kidney problems
  • Impaired respiratory function
  • Osteoporosis
  • Bone and joint problems
  • Tooth decay
Potential uses for Vitamin D

Research indicates that Vitamin D may also be useful in the treatment of:

  • Skin conditions, such as eczema or psoriasis
  • Colon and breast cancer
  • Osteoporosis
  • Arthritis
  • Bone and joint problems
  • Tooth decay
  • Migraine headaches

DISCUSSION

More about Vitamin D

In addition to enhancing both immune and thyroid function, Vitamin D also delivers calcium and other vitamins and minerals to our bones, teeth, and joints. And it doesn’t stop there… Vitamin D also aids in the absorption and functioning of these nutrients.

Structural strength

With age, we commonly experience degeneration of bone and joint health, indicative of increased injuries and a more sedentary lifestyle than in our youth. While it’s understood that calcium helps support our structural health, less is known of Vitamin D’s key role, though in regard to bone strength and density, it is arguably just as important. Without the Vitamin D delivery system, ingesting calcium is useless. It’s like buying veggies at the grocery store and leaving them in the car. Delivery is essential for utilization.

Functions

Vitamin D works by first delivering calcium and other minerals into the bloodstream and, from there, to bones, teeth, and joints. As a necessary aid in the building process and overall health of these areas, Vitamin D protects against degeneration, disease, and injuries.

Because we manufacture D in our bodies, this fat-soluble vitamin also functions as a hormone and is necessary for a healthy hormonal balance, as well as improving thyroid function. It is also needed for insulin levels and aids the metabolism of sugar.

The sunshine vitamin

Commonly, D is called the “sunshine” vitamin because it is the sun’s ultraviolet rays that stimulate the skin’s oils to produce it. Not surprisingly, many people, particularly those living in cloudy or smog-ridden environments — especially during winter months — are deficient since sun exposure is limited. This can result in structural and growth challenges; diminished health of bones, teeth, and joints; and lowered immune functioning.

Interestingly, darker skinned people need more sunlight (30 to 40 minutes 3 or 4 times a week) to produce adequate amounts of Vitamin D, as production through the skin is inhibited. Those with light skin, however, need only 15 to 20 minutes 3 or 4 times a week. And no need for sun worshippers to worry about stimulating too much Vitamin D; while the sun can cause other problems, this isn’t one of them.

In conclusion

Studies show that more than 14% of adults are Vitamin D deficient, though many of these same people ingest adequate amounts. If you’re staying away from the sun to protect your skin, you clearly care about your health. You may, however, cause other complications as your body is not stimulated to produce the necessary Vitamin D needed for optimal health. And if you’re staying away from fatty foods that contain the most concentrated amounts of D, supplementing might be the way to go — Vitamin D can usually be found in a high-quality multivitamin/mineral supplement.

NOTES ON USAGE

Amount

200 to 400 IU is recommended daily. For those with very little or no sun exposure, 400 to 800 IU is recommended.

Timing

Vitamin D is recommended with meals.

Synergists of Vitamin D

Recent research has demonstrated that taking Vitamin D with calcium can increase calcium absorption by up to 65%, even if you already have normal levels of Vitamin D.

Toxicity of Vitamin D

Amounts over 1,800 IU daily for extended periods may cause increased blood concentration of calcium, kidney stones, diarrhea, sore eyes, itchy skin, and unusual thirst.

Bans and restrictions

None reported.

RELATED RESEARCH

  • Chapuy, M.C., et al., “Prevalence of Vitamin D Insufficiency in an Adult Normal Population,” Osteoporosis Int 7.5 (1997) : 439-43.
  • Dawson-Hughes, B., “Calcium and Vitamin D Nutritional Needs of Elderly Women,” J Nutr 126.4S (1996) : 1165S-7S.
  • Lips, P., “Vitamin D Deficiency and Osteoporosis: The Role of Vitamin D Deficiency and Treatment with Vitamin D and Analogues in the Prevention of Osteoporosis-Related Fractures,” Eur J Clin Invest 26.6 (1996) : 436-42.
  • Reid, I.R., “Therapy of Osteoporosis: Calcium, Vitamin D, and Exercise,” Am J Med Sci 312.6 (1996) : 278-86.
  • Scragg, R., et al., “Effect of Winter Oral Vitamin D3 Supplementation on Cardiovascular Risk Factors in Elderly Adults,” Eur J Clin Nutr 49.9 (1995) : 640-6.
  • Woods, D.R., et al., “Vitamin D Deficiency in Florida, the Sunshine State,” J Fla Med Assoc 76.12 (1989) : 1035-6.