Asparagus Nutrition Calculator — Calories & Nutrition per Serving

Raw asparagus provides 52mcg folate per 100g (13% DV) — a meaningful amount that increases significantly with cooking. Boiled asparagus concentrates to approximately 149mcg folate per 100g (37% DV) because water loss reduces weight while folate is partially retained. Five steamed spears (93g) provide roughly 112mcg folate (28% DV) ^[1].

Iron: 2.14mg per 100g raw (12% DV) — among the highest for any common vegetable, comparable to spinach on a per-calorie basis (asparagus: 0.107mg iron per calorie vs. spinach: 0.118mg). Note that this is non-heme iron; absorption improves when consumed with vitamin C sources like lemon juice ^[2].

Thiamine (B1): 0.143mg (12% DV) and riboflavin (B2): 0.141mg (11% DV) — asparagus is one of the few vegetables providing meaningful amounts of both B vitamins simultaneously. Combined with its folate content, asparagus contributes to three different B-vitamin needs from a single food ^[1].

At 20 kcal per 100g with 2.2g protein, asparagus derives approximately 44% of its calories from protein — an exceptionally high ratio for a vegetable. Most vegetables range from 15-25% protein calories. This makes asparagus particularly calorie-efficient for protein contribution ^[1].

One cup of raw asparagus (134g) delivers 2.9g protein at 27 calories. A cup of cooked asparagus (180g) provides 4.3g protein at 40 calories. While asparagus alone won't meet protein targets, its protein density makes it a valuable addition to meals where total protein is being tracked ^[1].

The remaining macronutrient profile is equally lean: 0.12g total fat, 3.88g carbs, 2.1g fiber, 1.88g sugar, and just 2mg sodium per 100g. Asparagus is one of the lowest-sodium vegetables available — something worth noting for individuals tracking sodium intake closely ^[3].

A standard restaurant or home serving of asparagus is approximately 5 medium spears weighing ~93g. Raw, this provides: 19 kcal, 2.0g protein, 3.6g carbs, 2.0g fiber, 0.1g fat. This is roughly the caloric equivalent of a single tablespoon of olive oil — but with substantially more nutrients ^[1].

Those 5 spears deliver: 48mcg folate (12% DV), 2.0mg iron (11% DV), 188mg potassium (4% DV), 39mcg vitamin K (32% DV), and 5.2mg vitamin C (6% DV). The iron and folate contributions are the standout values for such a small serving ^[1].

Grilling or roasting those 5 spears with 1 tsp olive oil increases the total to approximately 56 kcal (from 19 + 40 for oil) — still a modest calorie count for a side dish. The oil adds virtually no carbs or protein but enhances fat-soluble vitamin (K, E, A) absorption ^[2].

Raw asparagus (20 kcal/100g): Maximum thiamine and riboflavin retention. Folate at 52mcg. Texture is crunchy; works well shaved thin in salads. Iron at its peak (2.14mg). Sodium almost negligible at 2mg ^[1].

Steamed asparagus (22 kcal/100g): Preserves most nutrients while softening texture. Folate rises to ~120mcg per 100g (concentration effect). Vitamin C slightly reduced but iron drops to ~1.5mg. Sodium stays very low at 3mg. This method offers the best overall nutrient-to-effort balance ^[1].

Grilled asparagus (50 kcal/100g with oil): Highest calories due to added oil, but the Maillard reaction creates compounds that enhance flavor without adding sugar. Folate drops to ~80mcg (higher heat degrades more). Vitamin C falls further. However, the oil significantly improves vitamin K and E absorption. Best for flavor; steaming is better for maximum nutrient retention ^[4].

Asparagus is a seasonal vegetable with peak harvest in April through June in the Northern Hemisphere. Out-of-season asparagus is typically imported from Peru, Mexico, or southern hemisphere farms. Research shows that fresh, in-season asparagus may contain 10-20% higher vitamin C and folate compared to imported spears that have traveled long distances ^[3].

Canned asparagus (available year-round) has a very different nutritional profile: 346mg sodium per 100g (vs. 2mg for raw) — a 173x increase due to added salt in canning liquid. However, canned asparagus retains 96mcg folate and 18mg vitamin C per 100g, and the convenience may make it a practical option when fresh asparagus is unavailable ^[1].

White asparagus — grown underground to prevent chlorophyll development — has a similar calorie count but lower vitamin A and slightly lower vitamin C compared to green asparagus, because the absence of sunlight reduces carotenoid and ascorbic acid synthesis. Green asparagus is the more nutrient-dense variety ^[2].