Vitamin D for Vegetarians: What Food Can and Cannot Do

Why vitamin D is the odd one out

Every other vitamin has a food-first answer. Vitamin D is primarily a hormone your skin manufactures from UVB sunlight, and food was always the minor contributor: even fish-eaters rarely cover the target from diet alone, and vegetarian diets supply less still. That is not a personal failing; it is the design of the nutrient.

Two honest numbers to hold: the adult reference intake is 15 ug (600 IU) a day, and a typical vegetarian day without fortified foods provides perhaps 1-3 ug. The full picture, including deficiency signs and interactions, is in our vitamin D guide.

Every vegetarian source, ranked honestly

• UV-exposed mushrooms, 100g: up to 10 ug. The one strong plant source, but only if the label says UV-treated or vitamin D mushrooms
• Fortified milk, 1 cup: about 2.5-3 ug
• Fortified soy, oat or almond milk, 1 cup: 1-3 ug, check the carton
• Eggs, 1 large: about 1 ug, concentrated in the yolk
• Fortified breakfast cereal, one serving: 1-2.5 ug
• Fortified spreads and some yogurts: 1-2 ug, label-dependent
• Butter and cheese: trace amounts only

A realistic vegetarian day, added up

Fortified cereal with fortified milk (4 ug), an egg at lunch (1 ug), and dinners featuring UV mushrooms twice a week (an average of 3 ug a day). That deliberate, slightly obsessive pattern averages around 8 ug, roughly half the target, and it is better than most people manage. This is why the honest conversation always ends at sunlight and supplements rather than another food list.

If vitamin D is a concern for you, set it as a focus in the planner: it will favour eggs, fortified milks and UV mushrooms where your diet allows, and its coverage dashboard will show you plainly when food falls short rather than pretending a salad fixed it.

Sunlight, winter and supplements, without the hype

In summer, regular short periods of midday sun on bare forearms let most lighter-skinned people synthesise plenty; darker skin needs longer for the same production, and sunscreen, glass and indoor life all reduce it. From roughly October to March at higher latitudes the sun is simply too low for skin synthesis, which is why bodies like the UK's NHS suggest everyone consider about 10 ug (400 IU) daily through winter, with year-round consideration for people with darker skin or little sun exposure.

That is general public-health guidance, not your prescription. Treating a suspected deficiency, or taking doses beyond that modest range, belongs with your doctor, who can test your blood level first; very high self-prescribed doses are genuinely harmful, and more is not better once you are replete.