Best One A Day Vitamin D3 in 2026

High-potency, bioactive vitamin D with vitamin K

Designed for patients with demonstrated increased nutritional needs for vitamin D*

Vitamin D promotes healthy bone formation and mineralization and supports immune and cardiovascular health*

High-potency, bioactive vitamin D with vitamin K

Provides 5,000 IU per softgel of vitamin D (as D3), designed for greater absorption

Includes bioavailable forms of vitamin K2 (menaquinone-7) to complement vitamin D

Supports bone, cardiovascular, and immune health*

Provides high-potency bioavailable vitamin D3 (325 mcg/5000 IU)

Available in easy-to-swallow softgels

Isoflavone activated support formula

Supports healthy immune function, bone density, and overall health*

Delivers soy isoflavones—genistin may help facilitate the body’s utilization of vitamin D3*

This non-GMO and gluten-free product delivers vitamin D3 solubilized in oil to support absorption in the intestinal tract*

Supports bone, cardiovascular, and immune health*

2,275 servings | Designed for easy, flexible dosing

Bioactive vitamin D in easy-to-swallow microtablet delivery form

Supports bone, cardiovascular, and immune health*

Delivers high levels of vitamin D to replenish vitamin D status*

Each MetaKids D3 Liquid dose provides 25 mcg (1,000 IU) vitamin D3

This product is non-GMO and gluten-free & supports bone and immune health*

Ideal for kids who prefer not to swallow tablets or capsules

Ultra Potent-C is a proprietary, patented, stomach-friendly vitamin C formula containing 500 mg vitamin C that features a buffered delivery system designed to help prevent the potential stomach upset sometimes associated with high vitamin C intake*

Ultra Potent-C supports healthy immune function and is a good source of antioxidants from vitamin C*

Metagenics D3 10,000 + K is high-potency, bioactive vitamin D with vitamin K designed for people with demonstrated increased nutritional needs for vitamin D*

This brand-new product provides vegetarian, bioavailable vitamin D3 (62.5 mcg/2,500 IU).

Supports bone, cardiovascular, and immune health: Vitamin D is important for maintaining healthy bone structure and is an important nutritional factor in the proper mineralization of bones. Vitamin D sufficiency may contribute to cardiovascular health and function. Vitamin D is important for maintaining healthy immune function.

With only three ingredients, this small tablet can be either swallowed or chewed, as it has a neutral, slightly sweet taste.

Isoflavones aid in utilization of vitamin D3 for enhanced health benefits

Aids in maintaining healthy bone strength and immune function

Formerly Iso D3

This brand-new product provides vegetarian, bioavailable vitamin D3 (25 mcg/1,000 IU).

Supports bone, cardiovascular, and immune health: Vitamin D is important for maintaining healthy bone structure and is an important nutritional factor in the proper mineralization of bones. Vitamin D sufficiency may contribute to cardiovascular health and function. Vitamin D is important for maintaining healthy immune function.

Get 150 1,000 IU servings in a single bottle; this easy-to-use spray has a unflavored and neutral taste.

Immune Active provides high potency vitamin C and zinc and features quercetin, NAC, and EGCG to help support a healthy immune response and promote antioxidant processes.*

Proprietary, patented vitamin C formula that features a buffered delivery system designed to help prevent the potential stomach upset sometimes associated with high vitamin C intake*

Supports healthy immune function and is a good source of antioxidants from vitamin C*