Sun-D3 | Vitamin D3 Cholecalciferol for Immune Function, Bone Health & Wellness | 3,000 IU or 10,000 IU | 90 Vegetarian Capsules

Sun-D3 — High-Potency Vitamin D3 Cholecalciferol for Immune Function, Bone Health & Overall Wellness

Sun-D3 delivers Vitamin D3 (cholecalciferol) — the most bioavailable and biologically active form of supplemental Vitamin D — in two potency options: 3,000 IU (75mcg) and 10,000 IU (250mcg). As a single-ingredient, pure Vitamin D3 supplement in a vegetarian capsule, Sun-D3 provides precise, flexible Vitamin D dosing for individuals who want to optimise their Vitamin D status under healthcare provider guidance.*

Serving size is 1 vegetarian capsule. Available in 3,000 IU and 10,000 IU potencies — select your preferred dose above.

Vitamin D3 — the sunshine vitamin and its critical roles

Vitamin D3 (cholecalciferol) is the form of Vitamin D synthesised in human skin upon exposure to UVB radiation from sunlight, and is the preferred supplemental form because it is more potent and more effective at raising and maintaining serum 25-hydroxyvitamin D [25(OH)D] levels than Vitamin D2 (ergocalciferol).*

Vitamin D insufficiency and deficiency are among the most prevalent nutritional deficiencies in the world — estimated to affect over 40% of adults in the United States and a significantly higher proportion in northern latitudes, darker-skinned individuals (who synthesise less D3 from sunlight), older adults (who have reduced skin D3 synthesis capacity), and individuals who spend limited time outdoors. Standard dietary intake typically provides only a small fraction of the body's Vitamin D requirement.*

Normal immune function — Vitamin D3 is one of the most important nutritional regulators of immune function. Vitamin D receptors (VDR) are expressed on virtually all immune cells — T cells, B cells, natural killer cells, macrophages, and dendritic cells. Active Vitamin D (1,25-dihydroxyvitamin D) modulates both innate and adaptive immune responses, supporting normal antimicrobial peptide production (particularly cathelicidin and defensin-β2), normal T-regulatory cell activity, and healthy inflammatory balance.*

Normal bone metabolism and calcium absorption — Vitamin D3's most established role is in normal calcium homeostasis. In the small intestine, active Vitamin D upregulates the calcium channel TRPV6, dramatically increasing intestinal calcium absorption. Without adequate Vitamin D, calcium absorption falls to 10–15% of dietary calcium; with adequate Vitamin D, absorption rises to 30–40%. Vitamin D also supports normal osteoblast differentiation and normal bone mineralisation, and activates osteocalcin — the calcium-binding protein that incorporates calcium into bone matrix.*

Normal muscle function — VDR expression in skeletal muscle supports normal muscle protein synthesis and normal neuromuscular function. Vitamin D deficiency is associated with proximal muscle weakness — Vitamin D sufficiency supports normal muscle strength and healthy physical performance.*

Normal cardiovascular health — VDR expression in cardiomyocytes, vascular smooth muscle cells, and endothelial cells supports normal cardiac function, healthy vascular tone, and normal blood pressure regulation. Vitamin D sufficiency is associated with normal cardiovascular health markers.*

Normal mood and neurological function — VDR expression throughout the brain, including in dopaminergic and serotonergic neurons, supports normal neurotransmitter synthesis and healthy mood regulation. Vitamin D supports normal serotonin synthesis and healthy brain function.*

Normal hormonal function — VDR expression in the testes and ovaries supports normal sex hormone production. Vitamin D sufficiency is associated with normal testosterone levels in men and normal ovarian function in women.*

3,000 IU vs 10,000 IU — choosing the right dose

The appropriate Vitamin D3 supplemental dose depends on an individual's baseline serum 25(OH)D level, which should ideally be determined by blood testing. General guidance:

3,000 IU (75mcg) — Appropriate for maintenance supplementation in individuals who are not severely deficient, for daily use alongside some sun exposure, or as a lower-dose option for children and adolescents (under healthcare provider guidance). Also appropriate for individuals sensitive to higher-dose supplementation.

10,000 IU (250mcg) — A high-potency dose appropriate for individuals with documented Vitamin D deficiency (<20 ng/mL), limited sun exposure, darker skin pigmentation, older adults, or obese individuals (who require higher doses to achieve adequate serum levels). Also commonly used in clinical protocols for repletion under healthcare provider supervision.

Serum 25(OH)D testing is recommended before and during supplementation at higher doses. Optimal serum levels are generally considered to be 40–80 ng/mL (100–200 nmol/L).*

At a glance — what this formula supports

• Normal immune function via Vitamin D receptor modulation throughout the immune system*
• Normal bone mineralisation and healthy calcium absorption*
• Normal muscle strength and neuromuscular function*
• Normal cardiovascular health and healthy vascular tone*
• Normal mood and neurological function via VDR brain expression*
• Normal hormonal function and healthy sex hormone production*

Quality you can verify

Every batch of Sun-D3 is manufactured in a GMP-certified facility, 100% vegetarian, non-GMO, and third-party tested for purity and potency.

90 vegetarian capsules per bottle. Available in 3,000 IU and 10,000 IU potencies.

*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.

Warnings

WARNING: If you are pregnant or breastfeeding, consult your physician before using this product. Vitamin D is a fat-soluble vitamin that can accumulate in the body — do not exceed recommended doses without healthcare provider guidance and periodic serum 25(OH)D monitoring. If you have hypercalcaemia, sarcoidosis, or other granulomatous conditions, consult your healthcare provider before use. If you are taking medications, consult your healthcare provider before use.