Vitamin D3 with Sea-Iodine by LifeExtension provides 5,000 IU Vitamin D, also called “the sunshine vitamin.” Vitamin D is a crucial nutrient that is normally obtained through the diet or produced by the skin after exposure to ultraviolet rays from the sun. Iodine is also included to help support the production of the thyroid hormones.

Vitamin D3 can be synthesized by humans in the skin upon exposure to ultraviolet-B (UVB) radiation from sunlight. But, due to winter season, weather conditions, and sun screen use, the body’s ability to produce optimal vitamin D levels may be inhibited.1 These factors point to the value of taking a daily vitamin D supplement. Vitamin D has long provided significant support for healthy bone density.2-8 However, scientists have also validated the critical role that vitamin D plays in regulating healthy cell division and differentiation, and its profound effects on human immunity.9-15 These findings link a deficiency of vitamin D to a host of common age-related problems. The current RDA for vitamin D is only 600 IU which has resulted in startling evidence of a widespread deficiency for this vitamin. Most experts in the field now recommend intakes between 1,000 – 10,000 IU for adults to achieve a serum 25(OH)D level above those indicative of vitamin D deficient levels, at approximately 80 nmol/L or 32 ng/mL. Life Extension suggests that healthy adults supplement each day with 5000-8000 IU of vitamin D with the objective of achieving an optimal 25-hydroxy vitamin D blood level between 50-80 ng/mL. A vitamin D blood test can help you determine the amount of vitamin D you need to supplement to achieve an optimal level.


The organic algae and potassium iodide found in Sea-Iodine™ provide you with over 667% of the Recommended Daily Value of iodine. Iodine is a health-promoting trace element essential for life. Its primary biological role lies in the production of the thyroid hormones triiodothyronine (T3) and thyroxine (T4).16 T4 and T3 contain four and three atoms of iodine per molecule, respectively. The thyroid gland actively absorbs iodide from the blood to make and release these hormones into the blood. Iodine happens to be found abundantly in sea vegetables and plants. In areas where no marine foods are eaten, people have lower iodine levels.17 For this reason, US commercial salt makers have long added iodine to deliver this key ingredient to your diet. However, we now know the concerns associated with eating too much table salt, which resurrects the dilemma of where to get healthy sources of iodine. Ironically, health-conscious people are often the most likely to develop low iodine levels.18 One reason is that athletes and people engaged in heavy physical effort deplete their natural stores of this trace mineral through perspiration. Vegetarians also have a substantially greater likelihood of low levels of iodine than omnivorous individuals, since foods of plant origin are less rich in iodine than animal-derived foods. One study demonstrated iodine deficiency in 25% of vegetarians and an incredible 80% of vegans.19 *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. Individual results may vary.

Label Information

Supplement Facts
Serving Size: 1 Capsule
Servings Per Container: 60
Amount Per Serving%DV
Vitamin D (as cholecalciferol)5000 IU1250%
Iodine [from Sea-Iodine™ Complex Blend (organic kelp and bladderwrack extracts, potassium iodide)]1,000 mcg667%
  • Suggested Use:

    Take one (1) capsule daily, or as recommended by a healthcare practitioner. This product is best utilized when taken with fat-containing, low fiber meals.

  • Storage: Store in a cool dry place. Keep out of reach of children.
  • Contraindications: Individuals consuming more than 2,000 IU/day of vitamin D (from diet and supplements) should periodically obtain a serum 25-hydroxy vitamin D measurement. Do not exceed 10,000 IU per day unless recommended by your doctor. Vitamin D supplementation is not recommended for individuals with high blood calcium levels. If you have a thyroid condition or are taking antithyroid medications, do not use without consulting your healthcare practitioner. When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating. Do not exceed recommended dose.
  • Other Ingredients: microcrystalline cellulose, vegetable cellulose (capsule), maltodextrin, modified food starch, silica, stearic acid.